and Review of Current Technology and Practices/67531/metadc... · 1 Introduction The cost of building and maintaining thermal distribution systems contributes substantially to the

jq# C l7~ANL-92/5

Materials and ComponentsTechnology Division



Detection and Locationof Leaks in District Heating

Steari Systems: Survey

and Review of CurrentTechnology and Practices

by D. S. K upperman, A. C. Raptis,and R. L. Lanham

Technoloav Division

Technology DivisicnMaterials and Components

Technology DivisionMaterials and Components

Technology Division

0Argonne National Laboratory, Argonne. Illinois 60439operated by The University of Chicagofor the United States Department of Energy under Contract W-31-109-Eng-38

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ANL--92/5

ANL-92/5 DE92 013740

Detection and Location of Leaks in District Heating Steam Systems:Survey and Review of Current Technology and Practices

D. S. Kupperman, A. C. Raptis,and R. N. Lanham

Materials and Components Technology Division

March 1992

Work supported by the MASTERU.S. DEPARTMENT OF ENERGY,

Assistant Secretary for Conservation and Renewable Energy,Utilities Systems Division

", j

TPL N c*: THI DOCUMENT IS UNLMITED

Contents

A re c t . . . . . . ............................................ ....................................................... 1

Ab s t r a c t .............................................................. 3

1 Introduction........................................................................................................... 3

2 B ackground .......................................................................................................... 4

2.1 Existing Techniques for Leak Detection and Location............. 52.1.1 Acoustic Emission..................................................................... 52.1.2 Infrared Spectroscopy ............................................................ 62.1.3 Tracer Gas.................................................................................... 72.1.4 E lectrical...................................................................................... 82.1.5 Summary of Existing Techniques...................................... 8

2.2 In-Stream Acoustic Monitoring of Leaks........................................ 9

3 Review of Literature Related to Acoustic Leak Detection inDistrict Heating Systems .................................................................................. 10

4 Survey of District Heating Leak Detection andSP c ................................................................................................ 1 2

4.1 Survey Method .......................................................................................... 134.2 R esu lts .......................................................................................................... 1 3

4.2.1 Leak Detection Practices ....................................................... 204.2.2 Interest in ANL Acoustic Technology.............. 264.2.3 European Experience.............................................................. 30

4.3 Conclusions from Survey....................................................................... 33

5 Acoustic Leak Location by Cross-Correlation Analysis.............. 35

5.1 Leak Location with a Commercially AvailableCorrelator at the ANL Steam Leak Facility..................................... 36

5.2 Leak Location with a Commercially AvailableCorrelator under Field Conditions .................................................... 36

5.3 Leak Location with a Research-Quality Correlatorunder Laboratory and Field Conditions..................... 38

5.4 Leak Location with an In-Stream Sensor ....................................... 38

6 C on clusions .......................................................................................................... 3 9

Acknowledgments ........................................................................................................ 40

References ....................................................................................................................... 41

111

Appendix A: Survey Form and Introductory Remarks for AcousticIak Detection and L o ........................................................ 43

Appendix B: Notes from Survey ............................................................................. 49

Figures

1 Basic Piping Designs...............................................................................19

Tables

1 U tilitiesSurveyed.................................................................................................. 14

2 B asic System D ata .................................................................................................. 15

3 Summary of Pipe Installations and Expansion Devices..........................17

4 Other System Details.........................................................................18

5 Location of Leaks....................................................................................................21

6 Leak Detection Methods ................................................................................... 22

7 Leak Location Methods...................................................................................... 23

8 General Interest in ANL Technology............................................................ 27

9 Specific Interest in ANL Technology........................................................... 31

iv

Detection and Location of Leaks in District Heating Steam Systems:Survey and Review of Current Technology and Practices

by

D. S. Kupperman, A. C. Raptis, and R. N. Lanham

Executive Summary

This report presents the results of a survey undertaken to identify andcharacterize current practices for detecting and locating leaks in districtheating (DH) systems, in particular steam systems. Currently usedtechnology and practices are also reviewed. In addition, the survey was usedto gather information of potential importance in the application of acousticleak detection. Discussion is included of a few examples of attempts tolocate leaks in steam and hot water pipes by correlation of acoustic signalsgenerated by the leaks.

Several leak detection techniques are currently available. Theapplication and effectiveness of each technique depend on the design andinstallation method of the DH piping, location of the leak (in the jacket orthe carrier pipe), system operating parameters, and knowledge of systemlayout and components. The most common systems used today areclassified according to their principle of operation, i.e., acoustic emission,infrared spectroscopy, tracer gas, and electrical.

Acoustic leak detection is potentially the most effective method forlocating leaks. However, sensors placed directly on the pipe outer wall maynot be effective enough to locate steam leaks by acoustic techniques in longruns of DH piping. One way to circumvent the general problem of steamleak detection in buried pipe is to insert an acoustic transducer inside thepipe to directly detect steam-propagated sound waves. This concept is thefocus of a program at Argonne National Laboratory (ANL) cofunded byConsolidated Edison of New York and NRG Thermal (a subsidary of NorthernStates Power).

The conclusions from the survey are presented below.

2

1. The extent to which leak detection is considered important varies

significantly from utility to utility. At least three of the larger utilities spend$1 million or more each year locating and repairing leaks. One-half of therespondents do not consider leaks to be a problem and/or are satisfied withcurrent leak location methods.

2. The most common leak location method is to feel the pavement todetermine hot spots and/or to focus on specific trouble-spot componentsusing as-built drawings.

3. Almost one-quarter (23%) of the respondents have found anacoustic technology useful to some extent in leak location, while 18% havetried an acoustic technology without success. The effectiveness of variousacoustic or vibration-sensing devices appears to depend on several factors,including the device used, staff expertise and experience, soil type, and pipedepth. One-half of the respondents who indicated that they found anexisting acoustic technology useful also stated that they are interested in theANL technology because they feel that current methods are not as effectiveas the respondents would like.

4. Most utilities are reluctant to do hot taps, and this presents asignificant potential barrier to the use of the proposed ANL leak detectionand location technology. (In a hot tap, a valve is attached to the pipe and amicrophone is inserted through the valve. The microphone need notremain in the pipe because the valve permits removal of the microphoneand isolation of the insertion hole.) Concern about hot taps appears to bebased on prior experience with large (several-inch) hot taps. However, themicrophone under development at ANL will employ a much smaller tap andmay relieve much of the present concern.

3

Abstract

This report presents the results of a survey undertaken to identify andcharacterize current practices for detecting and locating leaks in districtheating systems, particular steam systems. Currently used technology andpractices are reviewed. In addition, the survey was used to gatherinformation that may be important for the application of acoustic leakdetection. A few examples of attempts to locate leaks in steam and hotwater pipes by correlation of acoustic signals generated by the leaks are alsodiscussed.

1 Introduction

The cost of building and maintaining thermal distribution systemscontributes substantially to the cost of energy delivered to end users. Toimprove the competitiveness of existing DH systems, the capital, operating,and maintenance costs must be reduced. Thermal-distribution pipingsystems installed underground in densely populated areas are subject to avariety of internal and external conditions that reduce their performance.In particular, pipe leaks are a major cause of energy loss and maintenancecost over the life of a DH system. To minimize these losses and costs, leaksmust be detected, located, and repaired promptly.

This report presents the results of a survey undertaken to identify andcharacterize current practices for detecting and locating leaks in districtheating systems, in particular steam systems. The survey was used to gatherinformation on (a) characteristics of the distribution system that may beimportant for acoustic leak detection, (b) currently used technology andpractices, and (c) possible interest in acoustic leak detection technologysuch as that under development at Argonne National Laboratory (ANL). Inaddition, a review of leak detection technology and available literature onacoustic leak detection is presented. A few examples of attempts to locateleaks in steam and hot water pipes by correlation of acoustic signalsgenerated by the leaks are discussed.

4

2 Background

Leak detection and location techniques are currently available forseveral configurations of heat distribution systems carrying water. 1 Theperformance of these techniques has not been well documented by theindustry. Most of the existing data are in the possession of individual systemoperators and have not been collected and disseminated to the industry. Inthis report, the results of a survey of utilities is presented, eliminating thisprevious gap in information. Until now, the only readily available data onleak detection techniques and their application and performance are thosedocumented by an evaluation study conducted by the ConstructionEngineering Research Laboratory (CERL) of the U.S. Army Corps ofEngineers.2 The conclusions of the CERL study were that every availableleak-detection technique is limited in application to a specific conduitconfiguration and installation technique. With regard to acoustic leakdetection in particular, several researchers have investigated the applicationof acoustic leak detection to other systems, including nuclear reactors, withsome success.3 7

The major elements of an underground thermal distribution systemare distribution piping, thermal insulation, pipe supports, anchors,expansion/contraction devices, conduit/envelope structures, protectiveouter coverings, joint sealants, external drains, and manholes. Among thefactors that influence the design, materials selection, and installationmethods for thermal distribution systems are initial cost, service life,maintenance costs, thermal and economic efficiency, and safety. In thepast, performance improvements in thermal distribution systems have beenminor.

Underground piping systems are installed and operated in very harshenvironments and their long-term reliability is highly dependent oncorrosion protection, installation technique, site hydrology, and propermaintenance. After a few years of operation, most underground pipingsystems are likely to incur leaks in the carrier pipe. If not detected andrepaired promptly, these leaks can cause major damage to a whole section ofa piping system and neighboring utilities, as well as substantial energylosses. Most of the historical data on the causes of piping leaks in theUnited States have been derived from steam distribution facilities of thefederal government. These data indicate that leaks in underground pipingsystems are often caused by corrosion, mechanical rupture due to soil

5

subsidence and pipe expansion, or construction deficiencies. In a studyconducted by a Swedish national laboratory on the failure of Swedish DHhot-water distribution pipes from 1968 to 1982, several key causes of pipeleaks were identified. 1

Although steam leaks in underground pipes of DH systems may nothave the safety significance of a leak in a nuclear reactor, they can behazardous to the public and costly in terms of energy loss. In St. Paul,Minnesota, for example, one energy system lost 50% of its steam outputthrough leakage before the system was repaired. The U.S. Department ofDefense maintains about 6000 miles of heat distribution lines, mainlyunderground, and energy loss has become a concern. 2 A reliable leakdetection and location system for underground piping could reduce thecosts of operating a DH system and minimize the general liability of thecompany providing the service. However, the task of finding leaks iscomplex because of the configuration of the distribution systems. Insulatedheat-carrying pipe, for example, can be supported inside a protective buriedonduit with an air space between the pipe insulation and the conduit's

inner wall. Supply and return lines can be in common or separate conduits.Alternatively, a concrete trench with removable covers can contain insulatedsupply and return lines.

2.1 Eristing Techniques for Leak Detection and Location

Various leak detection techniques are currently available. Theapplication and effectiveness of each technique depend on the design andinstallation method of the DH piping, location of the leak (in the jacket orthe carrier pipe), system operating parameters, and knowledge of systemlayout and components. The most common systems today are classifiedaccording to principle of operation as follows: acoustic emission, infraredspectroscopy, tracer gas, and electrical.

2.1.1 Acoustic Emission

When a leak occurs in a pipe carrying pressurized hot water or steam,the turbulent flow of the fluid passing through the crack or hole generatessound waves. These waves are omnidirectional and their intensity decreasesinversely with distance from the leak. Commercially available acoustic leakdetection and location systems incorporate acoustic sensors to detect andmeasure the intensity of the noise signal generated by a leak. Acoustic

6

signals can be detected by placing a sensing microphone in direct contact

with a carrier pipe at an accessible point. This method is more effective forwater-filled pipe because the sound in the water is coupled to the pipe walldue to the relatively small difference in acoustic impedances. For asteam-filled pipe, the acoustic impedance mismatch is much greater andthe sound propagating in the steam is not transferred readily to the pipewall; thus, sensors that detect leak noise by being placed on the pipe wallwould be less efficient than a sensor that could be inserted into the pipe.

Another approach to measuring the intensity of the acoustic leaksignal is bar-holing, in which a metal rod is driven into the ground toestablish metal-to-metal contact with the carrier pipe. The metal rod actsas a waveguide and the acoustic signal is measured at the upper end of therod. To locate the leak, multiple acoustic wave measurements are taken.The location is then found by comparing the measured intensities of theleak signal at various locations and identifying the point where it is highest.Another method is to move a microphone, in contact with the ground, alonga path following the pipe and use the maximum-amplitude noise signal tolocate a leak. The success of this method depends on the skill of theoperator and the configuration of the underground piping.

A more sophisticated and potentially cost-effective acoustic leakdetection/location technique requires only two measurements of theleak-noise signal and uses an advanced computerized system to analyze thesignals and locate the leak via a cros: :orrelation function. This function is amathematical concept that can be b epresented by a graph that plotsamplitude over time. In the absence of a leak, the graph is generally a seriesof small bumps caused by background noise. The appearance of a large peakindicates a leak. Time (how long it takes the signal to travel from the sourceto one of the two sensors) is easily converted to distance. By comparing thetime delays in signals received by the two sensors, we can accuratelypinpoint the leak.

2.1.2 Infrared Spectroscopy

A leaking steam pipe could increase the temperature of the groundand surface area above the leak. If the ambient temperature, depth of theleaking pipe, and variations in ground-surface temperature are withincertain limits, leaks can be detected by infrared spectroscopy. Atemperature profile of the surface above the pipeline, taken with a camera

7

mounted on a motor vehicle or helicopter, is compared to a referencetemperature profile taken when there were no leaks in the pipeline. Also,temperature-reading devices can be used to identify variations in groundtemperature and hot spots on the ground surface along the pipeline route.Hot spots identified by infrared spectroscopy are likely to be the locations ofpipe leaks.

Infrared spectroscopy is most effective when a leak occurs in both thecarrier pipe and its jacket at the same location. Soil condition, pipe systemdesign, installation technique, and leak type are critical factors in theapplication and effectiveness of this method. With certain ground soilconditions and installation techniques, leaking hot water may spread intothe surrounding soil and blur the leak source or it may be absorbed by thesoil and limit the effectiveness of the method. Accuracy is also limited whena leak occurs only in the carrier pipe or the jacket, and when there aremultiple leaks in the pipe system. In general, this method is not applicablein many commonly occurring leak situations and it is expensive.

2.1.3 Tracer Gas

The tracer gas method can be used to detect and locate leaks inunderground heat distribution systems that employ a double wall with anannular space between the carrier and the casing pipes. Heat distributionbased on this pipe design is found mostly in federal governmentinstallations. Leaks can be detected and located in both the carrier andcasing pipes. Gas is injected into the pipe system and its concentration ismeasured at the surface or in shallow bar-holes made at intervals about equalto the average depth of the conduit along the entire length of the pipesystem. The hole with the highest gas concentration will usually indicatethe location of the leak. Sulfur hexafluoride (SF6) is the most frequentlyused tracer gas because it does not occur naturally. Although this techniqueis feasible for detecting leaks in double-walled piping systems, it is notwidely used. A major disadvantage is the need to shut down the heatdistribution system when the carrier pipe is tested. Calculations todetermine diffusion time and leak location are often difficult. In testing forcasing leaks, a scan of the surface to detect the tracer gas and locate theleak is not always reliable because, depending on soil conditions, the leakinggas may either travel vertically or follow the path of least resistance.

8

2.1.4 Electrical

Most of the recently built DH hot water piping systems in the UnitedStates and Europe have factory-made insulated pipes that incorporateelectrical devices for detecting and locating leaks. To detect leaks in thecarrier pipe and casing, an exposed wire is installed in the pipe insulation;the electrical resistance between this electrical conductor and the metalcarrier pipe can then be measured and monitored. Leaks can be detected bycomparing the measured resistance with a minimum reference value.Another electrical method for locating leaks is based on time-domainreflectometry. When the outer braid of a coaxial cable, installed in the pipeinsulation, is infiltrated by a leaking fluid (groundwater from a leak in thecasing or hot water from a carrier pipe leak), it undergoes a change incharacteristic impedance at the leak. This change converts outgoingelectrical signals from the plant into reflected pulses or standing waves. Tolocate the leak, the signals are detected and analyzed at the plant withsignal-processing equipment.

The currently available electrical techniques for detecting and locatingleaks are used with preinsuiated pipe systems. These techniques have onlybeen used in the last 10-15 years in hot-water piping systems, and existingheat distribution installations cannot be retrofitted cost-effectively. Thelong-term reliability of electrical techniques has not been proved.Corrosion, the most common problem with underground piping systems, islikely to limit the life of the signal wires and reduce the long-termeffectiveness of this system.

2.1.5 Summary of Existing Techniques

All of the commonly used leak detection techniques have limitations.The infrared method is limited by high cost and "blurring" of the hot spot asheated water spreads into the surroundings or is directed away from thesource of the leak. Accuracy of the tracer gas method is limited by variationsin gas diffusion rates and preferential migration. Another disadvantage ofthe tracer gas method is that the DH system must be shut down when thepipes are tested. Electrical methods pose reliability problems and cannot beused in older systems. The acoL'stic method, though somewhat of an "art" inpractice, currently has the greatest potential for detecting leaks inunderground pipes.2

9

2.2 In-Stream Acoustic Monitoring of Leaks

Transducers or transducer/waveguide systems placed directly on thepipe outer wall may not be effective enough to locate leaks acoustically inlong runs of DH piping. Two factors contribute to the problem with

steam-filled pipes. The first is that acoustic impedance mismatch betweenthe pipe wall and the steam is so great that the amount of sound energycoupled into the pipe froi the steam is limited. (Sound traveling inside awater-filled pipe is efficiently coupled to the pipe wall and can be detectedby externally mounted transducers.) The effectiveness of cross-correlationanalysis for leak location in steam-filled pipes is further reduced by thenumerous modes of acoustic wave propagation present in the pipe wall.These modes are not normally present in water-filled pipes because of thedamping effect of the water.

One way to circumvent the general problem of steam leak detection inburied pipe is to insert an acoustic transducer inside the pipe for directdetection of steam-propagated sound waves. We briefly evaluated acapacitance-microphone-type transducer (Knowles Electronics, Inc., ModelBT-1834) that can be inserted into a pipe through a small hole. Thetransducer was inserted into the ANL test pipe through a hole used forartificial leaks. An Endevco 2224C accelerometer was placed on the outerwall of the pipe at the same location. The pipe was filled with gas at~6 psi pressure. The transducer showed superior signal-to-noise ratios overmost of the examined frequency range.' For example, near 4 kHz, thesignal-to-noise ratio for the capacitance microphone transducer is about 10dB higher than for the accelerometer. This advantage is reduced by a fewdecibels at higher frequencies (e.g., 10-12 kHz). Cross-correlation analysisof signals from a gas leak also suggests that these small transducers can besignificantly more effective than transducers mounted on the outside of thepipe. A well-defined correlation peak for a leak could not be obtained withexternally mounted accelerometers, whereas it could be with in-streamtransducers.

A potential problem with this concept is that, for continuousmonitoring, the transducer must be protected from the erosive andcorrosive effects of the fluid stream, as well as from the elevatedtemperatures. Furthermore, the sensor must be inserted so that the fluiddoes not create high levels of acoustic noise as it flows past the sensor.These problems can be overcome, and the advantage of not having to analyze

10

propagation modes in the pipe wall makes the pursuit of an intrusive sensorparticularly attractive for correlation analysis. A goal of the current programat ANL is the development of an in-stream acoustic sensor for steam leaklocation.

3 Review of Literature Related to Acoustic Leak Detection inDistrict Heating Systems

Several papers on the detection and location of leaks are brieflyreviewed below. In general, attempts to locate leaks acoustically haveconcentrated primarily on water filled pipes. No papers dedicated todetection and location of stear leaks have been found. In general, locationof leaks in water-filled pipes have been successful. Other references arepresented at the end of this report.

Ref. 8 "Acoustic leak location in district heating pipes."Fuchs, H.V., Frommhold, W., Poggemann, R., and Zenker, P.(Correlation analysis)Source: HLH, Heizung, Luftung, Klimatechnik, Haustechnik, v. 42:1;Fraunhofer-Institut fur Bauphysik, Stuttgart, and EnergieversorgungOberhausen AG (West Germany),Language: German

Leaks were found using LOKAL ('leak location through correlation. analysis"). Only water leaks were detected. Leaks were detectedwith frequencies less than 1 kHz and sensors placed on the pipeouter walL Location was by cross-correlation analysis. Leak ratescJ 0.05 to 3.5 m3/hr. were detected at distances up to 260 m.

Ref. 9 "Computer-aided measuring system for automatic monitoring of pipenetworks and leak detection." Schwarze, H.(Noise-correlation technique)Source: Technisches Messen, v. 55, no. 7-8, 1988, pp. 279-285;Fachhochschule Bielfeld, Bielfeld, West Germany.Language: German

Location of pipe leaks is determined by employing an LSI chipTDC1028 and three radio links to calculate the cross-correlationfunction. This work involves detection of water leaks only. The

11

frequencies of interest are 20 Hz to 10 kHz. Microphones areattached to hydrants. Electronic filters provide flexibility in selectionof frequencies (100 Hz to 5 kHz).

Ref. 10 "Leakage monitoring in synthetic jacket pipes for district heatingsupply." Micheel, H. J. (Impulse echo measurement)Source: Fernwarme International, v. 16, no. 6, Nov.-Dec. 1987, pp.380-385;Salzgitter Elektronik GmbH, Kiel, West Germany.Language: German

With a network of moisture indicators and wire leads, the location ofleaks is determined by insulation resistance measurement and impulseecho measurement.

Ref. 11 "Environmental monitoring technologies". Chang, D. B., Pierce, B.M., and Shih, I. Source: SAE Technical Paper Series 910190,International Congress and Exposition, Detroit, Michigan, Feb. 25-March 1, 1991Language: English

This paper discusses a fiber-optic liquid level sensor that may providean accurate measurement of leakage from underground storage tanks.Leaks are detected by measuring the change in light intensitytransmitted along a special fiber-optic cable. When the cable is incontact with the liquid (as it could be if it were buried and in contactwith a leaking fluid), the transmitted light is attenuated.

Ref. 12 "Leak location in district heating networks using acousticalcorrelation techniques." Turtiainen, H.(Acoustic correlation techniques)Source: Valtion Teknillinen Tutkimuskeskus, Espoo, Finland.Language: Finnish

The theoretical and applied sides of leak location through acousticcorrelation are based on experience with 17 real leaks.

Ref. 13 "In situ control of district heating networks." Gransell, H. andLjungquist, John.(Damage analysis and on-site measurements)

12

Source: Annual Conference of the Int'l District Heating Assn., v. 76;Studsvik Energiteknik AB,Language: English

Reports on damage analysis and on-site measurements, and describesmethods for leak detection.

Ref. 14 "Active acoustic detection of leaks in underground natural gas

distribution lines." Jette, A. N., Morris, M. S.; Murphy, J. C.; andParker, J. G.

(Field measurements, theoretical elastic waves, optical vibration

sensor)Source: Materials Evaluation, v. 35, no. 10, Oct. 1977, pp. 90-96, 99;Johns Hopkins University, Baltimore, Maryland, USA.Language: English

Describes research. program aimed at understanding the acousticdetection of leaks in pipes.

Ref. 15 "Pipeline leak location using radiotracer technique." Eapen, A.C.,Ajmera, R.L., and Agashe, S.M.(Radiotracer technique)Source: Bhabha Atomic Research Centre, Bombay, India - Isotope Div.Language: English

Compares new radiotracer technique to other leak detection

techniques.

i

4 Survey of District Heating Leak Detection and Location Practices

This survey was undertaken as part of a joint program between theU.S. Department of Energy and utilities that operate district heating andcooling systems. The objective of the joint program is the development ofan in-stream acoustic sensor to locate steam leaks. The survey itself wasaimed at identifying and characterizing current practices for detecting andlocating leaks in district heating systems, specifically steam systems. This

13

information reflects the conditions, needs, and requirements of the DHindustry in developing acoustic leak detection technology

4.1 Survey Method

The survey was conducted through telephone contacts with utilitymembers of the International District Heating and Cooling Association(IDHA). Introductory remarks used in the survey, and the form used torecord the information obtained, are included in Appendix A.

The survey was designed to gather information in three major areas:(a) characteristics of the distribution system that may be relevant to designand implementation of the acoustic leak detection technology,(b) technologies and practices currently used by the utility to detect andlocate leaks, and (c) interest in utilizing the acoustic leak detectiontechnology developed by ANL.

Results of the survey are summarized below, and detailed notes areprovided in Appendix B.

4.2 Results

There are 59 companies listed as "utility" members of the IDHA. Ofthese, 3 are European, 4 are Japanese, 5 are planning systems that are notoperational yet, and. 3 are holding companies that own a number ofoperating district heating and cooling systems. All 44 of the operationalNorth American district heating and/or cooling system companies weresurveyed. Table 1 shows the names and telephone numbers of thecompanies and individuals contacted. In addition, investigations ofEuropean leak detection practices were made and summarized.

In Table 2, basic system data arc summarized. Of the 44 companiescontacted, 30 provide steam only, 9 provide steam plus chilled water and/orhot water, 2 provide hot water only, and 2 provide hot water and chilledwater.

Some of these systems have had pipe in the ground for many years. Ofthe 31 systems for which age data were given, 17 were at least 60 years old.

14

Table 1. Utilities Surveyed

Name of system Contact person Phone

Alabama Power CompanyBaltimore ThermalBoston ThermalCentral Heat Distribution (Vancouver)Cleveland ThermalCogeneration Management CompanyConcord SteamConsolidated EdisonDayton Power and LightDetroit EdisonDistrict Energy St. PaulEnergy Networks Inc.Energy Systems Co. - OmahaEugene Water and Electric BoardFairbanks Municipal UtilitiesGeorgia Power Co.Harrisburg Steam WorksIndianapolis Power and LightJamestown Board of Public UtilitiesKent County Public WorksLansing Board of Power and LightMid-America Energy ResourcesMinneapolis Energy CenterNashville ThermalNRG ThermalPacific Energy/Central Plants Inc.Pacific Gas and ElectricPACT, Ltd.Philadelphia ThermalPittsburgh ThermalPublic Service Co. of ColoradoRochester District Heating CooperativeSt. Louis ThermalSeattle SteamToronto District Heating Corp.Trenton District EnergyTrigen - TulsaTrigen - London, OntarioTrigen - Kansas CityTrigen - Nassau CountyUnited IlluminatingWillmar Public UtilitiesWisconsin ElectricYoungstown Thermal

Dale DambachBrian BoorAlan MurphyJim BarnesRick PucakDon YeapleMark SaltzmanTony CodnerHenry RoutzohnTerry SchumaierRay SchmidtJeff LindbergDave WoodsDennis DaggettJohn P. StenbergRobert StewartJan SockelFred BrasherDoug ChampBill AllenJoette Woodard-YaukDavid KieselGary GustafsonRoger BeckhamMark AndersonVic DillowayRich MayerBob SazioSteve SmithJim CummingsDennis EliotHoward ConeArt StanzeWoody WoodardAlex BystrinDon LeibowitzKen AdamsGary NickersonBob StevensonAl GusslerCraig BradleyBart MurphyTom VentmigliaRich Burns

205-226-1880301-625-2222617-482-9550604-688-9584216-241-5980617-732-2700603-224-1461215-576-2440513-227-2481313-237-5290612-297-8955203-727-3095402-346-9066503-484-2411907-459-6259404-526-4678717-234-4600317-261-8854716-483-7582616-774-3694517-371-6780317-261-8893612-349-6072615-244-3150612-373-5335213-725-1139415-973-3828412-642-7446215-875-6911412-231-0409303-573-4397716-546-8890314-621-3550206-623-6366416-392-6838609-396-1892918-582-2212519-434-9194816-556-2821609-396-7651203-787-7200612-235-4422414-221-2491216-743-7712

15

Table 2. Basic System Data

Servicesprovided

Max. age Annual Miles (S = steam;of pipe sales of HW = hot water

Name of system (yr) (106 Btu)a pipe CW = cooling)

Alabama Power CompanyBaltimore ThermalBoston ThermalCentral Heat Distribution (Vancouver)Cleveland ThermalCogeneration Management CompanyConcord SteamConsolidated EdisonDayton Power and LightDetroit EdisonDistrict Energy St. PaulEnergy Networks Inc.Energy Systems Co. - OmahaEugene Water and Electric BoardFairbanks Municipal UtilitiesGeorgia Power Co.84Harrisburg Steam WorksIndianapuiis Power and LightJamestown Board of Public UtilitiesKent County Public WorksLansing Board of Power and LightMid-America Energy ResourcesMinneapolis Energy CenterNashville ThermalNRG ThermalPacific Energy/Central Plants Inc.Pacific Gas and ElectricPACT, Ltd.Philadelphia ThermalPittsburgh ThermalPublic Service Co. o% ColoradoRochester District Heating CooperativeSt. Louis ThermalSeattle SteamToronto District Heating Corp.Trenton District EnergyTrigen - TulsaTrigen - London, OntarioTrigen - Kansas CityTrigen - Nassau CountyUnited IlluminatingWillmar Public UtilitiesWisconsin ElectricYoungstown Thermal

70

6022

1560

89858

2480

84

77083

1

178

8070

90110

100308

21

852039

8690

Total

548,5221,b46,400 #

998,4731,399,648 #

300,00037,298,000

3,957,353824,557

1,003,932

467,881 #135,360 #107,300357,700

5,681,900

695,5681,882,858

1,714,208398,503

722,646

4,498,800598,882

1,038,000 #

999,559986,280

2,586,000447,000

120,000

55,6542,160,274

496,320

74,127,578

6 S15 S22 S5 S19 S1.5 S8 S

100 S15 S41 S20 MW17 S, HW, CW

S CW9 S

S, HW28 S7 S

S6 S

1.5 S12 S

Cw4 S, HW, CW

S, CW5.5 S

S, HW, CW11 S7 S

33 S1 S,CW11 S9 S

22 S18.5 S

12 SHW

2 S,CW4 S9 S9 HW, CW<1 HW, CW4 HW, S

28 S6 S

529

aFor 1989 except where marked with # (1988 data).

16

Two measures of system size are shown: annual energy sales and milesof supply piping. Although these data were not available for all utilities, thetotal energy sales for the utilities with such data was more than 74 x 1012Btu, and the total length of supply pipe was 530 miles. This information willbe useful in weighting the Importance of the responses. For example, theneeds of Consolidated Edison, with more than 50% of the total sales and25% of the supply piping, are extremely significant.

Table 3 summarizes the types of piping installations and expansiondevices used. Box conduit, solid pour, and prefabricated pipe conduit typesare it istrated in Fig. 1. While 41% of the respondents use prefabricatedconduit (pipe-within-pipe), this is often only their newer pipe. A majorexception is Consolidated Edison, whose standard design is a pipe-within-pipe with an annular space between the two.

The next most common installation is box conduit (36%), followed bydirect bury (32%), solid pour (25%), and tunnels (14%). Although nodefinite figures are available, box conduit probably represents the greatestnumber of pipe miles for utilities other than Consolidated Edison.

Slip joints and bellows are by far the most common expansion devices,and many utilities use both types. Slip joints are used by 57% of therespondents, and bellows by 55%, while only 9% use ball joints and 23% useexpansion loops.

Typical or average intervals between expansion devices and betweenmanholes are indicated in Table 4. The interval between expansion devicesis relevant due to the acoustic attenuation caused by such devices if sensorsare placed on the pipe surface. Interval between manholes is important if itis possible that the hot tap required for the ANL acoustic detection devicecan be done at manholes to minimize costs.

Of the 35 utilities providing steam pressure data, 16 provide highpressure and low pressure steam service (low pressure is defined here as 50psi or less), 14 provide only high-pressure service, 2 provide only low-pressure service, and 1 distributes 800-psi superheated steam.

Of the 32 systems providing high-pressure service, 15 operated at150 psi or less. Only 7 systems operated at pressures over 200 psi.

17

Table 3. Summary of Pipe Installations and Expansion Devices

Types of pipe Types ofinstallationsa expansion devicesb

Name of system BC SP T PC DB S Bel B EL

Alabama Power CompanyBaltimore ThermalBoston ThermalCentral Heat Distribution (Vancouver)Cleveland ThermalCogeneration Management CompanyConcord SteamConsolidated EdisonDayton Power and LightD'troit EdisonDistrict Energy St. PaulEnergy Networks Inc.Energy Systems Co. - OmahaEugene Water and Electric BoardFairbanks Municipal UtilitiesGeorgia Power Co.Harrisburg Steam WorksIndianapolis Power and LightJamestown Board of Public UtilitiesKent County Public WorksLansing Board of Power and LightMid-America Energy ResourcesMinneapolis Energy CenterNashville ThermalNRG ThermalPacific Energy/Central Plants Inc.Pacific Gas and ElectricPACT, Ltd.Philadelphia ThermalPittsburgh ThermalPublic Service Co. of ColoradoRochester District Heating CooperativeSt. Louis ThermalSeattle SteamToronto District Heating Corp.Trenton District EnergyTrigen - TulsaTrigen - London, OntarioTrigen - Kansas CityTrigen - Nassau CountyUnited IlluminatingWillmar Public UtilitiesWisconsin ElectricYoungstown The-rmal

0 " " "

0

" 0

0 0

"

"

" S 0

" " 0

0

0

" "

" "

"

"

"

S

"

"

"

0

"

0

"

"

" "

"

" " "

" "

" "

S

0

"

S

0

0

"

"

"

"

"

"

"

A

"

0

0

" "

" "

" "

"

"

" "

"

" "

0 00

S"

0

0

0

0

"

"

0

"

0

"

"

"

"

"

"

"

"

0

S "

"

S 0 0

" " 0 0

0

""

Totals% of respondents

aPipe Installations: BC = Box conduit; SP =or other pipe-within-pipe; DB = Direct Bury

Solid pour; T = Tunnel; PC = Prefabricated conduit

bExpansion Devices: S = Slip; Bel = Bellows; B = Ball; EL = Expansion loop.

0

0

0

" 6

"

"

0

0 0

0

0

1636

1125

6 1814 41

1432

2557

2455

49

1023

18

Table 4. Other System Details

Typicalor Maxcmin OndksteavragIntervalsa pose rdirn

BetwneeolesLwesNamefsystem erliuits manholes HP IP Yes No


TotalsAverage of responses% of respondents

20020075

200

20075450

100

750

150200

450400

350200300

125

200

150

100

125350

243

400

200460

100

500100450350750250375

200200

550250

350200600

125225500200325

250400

350350

349

150180 35190190

, 150 22

165200190 7125 50180150125250 15

5090 10.150 30250 15

150 15265 15

250150b

125150225230125 30200

140 20250 25

150

185 15

10160 12150 15

176 22

a8tailsjrwvidx1 inAppRndixR povidesxheatedsteamat pet. Qxdsteis150psi.

0

I

"

"

"

"

"

"

"

"

"

I

"

"

"

"

"

S

"

"

0

0

"

"

"

"

"

"

"

"

"

11

NA

S

NA

2

22

AL a 7D 7U 7D2ay% Kn0% I

19

POLYTHYLENE MEMBRANE

CORRUGATED- d " .o STEEL

AIR SPACE

INSULATION WITHWATERPROOFMEMBRANE

- ' U* SUPPORT

Box type concrete conduit

REMOVABLE COVE

P .UPR

PIPE SUPPORT

Removable cover on box type conduit

6 MIL POLYTHYLENE MEMBRANELAID ON TOP OF EMULSION

INSULATION WITHWATERPROOF MEMBRANE

1/21 ANNULAR SPACE

-+STEAM MAIN

DRAIN PIPECRUSHEDGRAVEL

Solid pour conduit Metal casing, prefabricated conduit

Fig. 1. Basic Piping Designs (from "District Heating Handbook, FourthEdition," International District Heating and Cooling Association, 1983)

MET AL

CASING

ONDE NSATE

RETURN

INSUL ATION

1

. , C

I

"co

" /

/*

20

"External sources" was cited as the most common leak problem (Table5). For example, leaks in city water mains and salt-laden street drainage aretwo important types of external sources. The specific location of the leak inthe distribution system would vary depending on the location of the externalsource.

Expansion devices are the most common specific locations of leaks;30% reported that this is a trouble spot. Most of the systems withcondensate return indicated that the condensate pipe is their biggest leakproblem. Other trouble spots, in descending order of importance, areflanges, welds, valves, steam traps, rollers, and tees.

Eight steam companies indicated that they have condensate return. Ofthese systems, 44% indicated that the condensate pipe is their biggest leakproblem.

4.2.1. Leak Detection Practices

In this report a distinction is made between "detection" (determiningthat a leak exists) and "location" (establishing the location of the leak).

Almost 75% of the respondents indicated that their primary means ofdetecting leaks is a report of visible steam from a manhole or customerinstallation (Table 6). Infrared is used by 11%, while 9% monitor makeupwater requirements to detect leaks. In-line electrical leak detection systemswere installed in five systems, but only three are being used. The othershave been abandoned due to extensive problems with false alarms and otherdeficiencies.

Several systems with condensate returns will typically replace anentire section of condensate line rather than attempt to locate the leak,because of general deterioration of the line.

Three-quarters of the respondents have found one or more methodseffective to some extent in locating leaks (Table 7). Generally, once a leak isdetected, its location is isolated between two manholes on the basis ofvisible steam. Because certain types of system components are weak spots(Table 4), as-built drawings are used to narrow down the possible location.Simply feeling the surface of the pavement for hot spots is used by 34% ofthe systems. Some type of acoustic technology is used by 23%, while 16%use infrared for locating leaks.

21

Table 5. Location of Leaks

Primary location of leaksa

Name of system ED Ex Tr W V F R CP T

Alabama Power CompanyBaltimore ThermalBoston ThermalCentral Heat Distribution (Vancouver)Cleveland ThermalCogeneration Management CompanyConcord SteamConsolidated EdisonDayton Power and LightDetroit EdisonDistrict Energy St. PaulEnergy Networks Inc.Energy Systems Co. - OmahaEugene Water and Electric BoardFairbanks Municipal UtilitiesGeorgia Power Co.Harrisburg Steam WorksIndianapolis Power and LightJamestown Board of Public UtilitiesKent County Public WorksLansing Board of Power and LightMid-America Energy ResourcesMinneapolis Energy CenterNashville ThermalNRG ThermalPacific Energy/Central Plants Inc.Pacific Gas and ElectricPACT, Ltd.Philadelphia ThermalPittsburgh ThermalPublic Service Co. of ColoradoRochester District Heating CooperativeSt. Louis ThermalSeattle SteamToronto District Heating Corp.Trenton District EnergyTrigen - TulsaTrgen - London, OntarioTrigen - Kansas CityTrigen - Nassau CountyUnited IlluminatingWillmar Public UtilitiesWisconsin ElectricYoungstown Thermal

Total

S

" "

0

0 0

"

S "

"

"

"

"

0 0

0

" "

"

"

" 0 .

0

0

0 0 0

0

9

0

"

"

" "

"

"

"

"

"

"

"

"0

0

0

" "

" a

13 15 2 6 4 5 2 8 1

% of respondents 30 34 5 14 9 11 5 18 2

aED = Expansion devices; Ex = Leaks due to external causes; TR = Traps; W = Welds: V = Valves;F = Flanges; R = Rollers; CP = Condensate pipe; T = Service Tee.

22

Table 6. Leak Detection Methods

Methods used for detecting leaks

Visible Infra- Makeup Wire in DepthName of system steam red water conduit of pipe


Total

% of respondents

0 3-4I

"

"

"

"

"

"

I

I

"

"

"

"

"

"

"

"

0

e

"

S

"

"

"

"

"

"

"

"

"

"

"

"

"

0

32 5 4

73 11 9

10

0

3-98-102-42-8

2-154-6

3-102-10

"

0

8

"

"

2-90

0

4-10

5-183-10

3

7

23

Table 7. Leak Location Methods

Methodstried

withoutMethods found useful a success

Name of system FS A IR Other A IRAlabama Power CompanyBaltimore ThermalBoston ThermalCentral Heat Distribution (Vancouver)Cleveland ThermalCogeneration Management CompanyConcord SteamConsolidated EdisonDayton Power and LightDetroit EdisonDistrict Energy St. PaulEnergy Networks Inc.Energy Systems Co. - OmahaEugene Water and Electric BoardFairbanks Municipal UtilitiesGeorgia Power Co.Harrisburg Steam WorksIndianapolis Power and LightJamestown Board of Public UtilitiesKent County Public WorksLansing Board of Power and LightMid-America Energy ResourcesMinneapolis Energy CenterNashville ThermalNRG ThermalPacific Energy/Central Plants Inc.Pacific Gas and ElectricPACT, Ltd.Philadelphia ThermalPittsburgh ThermalPublic Service Co. of ColoradoRochester District Heating CooperativeSt. Louis ThermalSeattle SteamToronto District Heating Corp.Trenton District EnergyTrigen - TulsaTrigen - London, Ontariob' rigen - Kansas CityTrigen - Nassau CountyUnited IlluminatingWillmar Public UtilitiesWisconsin ElectricYoungstown Thermal

Total% of respondents

0 "

0

"

"

"

I "

0

"

"

"

"

"

"

Leaks not a problem

Leak obvious in tunnel

" Dry spot on rainy day

Leaks not a problem

Use elec. probe if needed0 0

0

In-line elec. system0

S

"

Hand-held thermal meterLeaks not a problem

" Leaks obvious in tunnelsEscape of vapor or waterEscape of vapor or water

0

"

"

0

Leaks not a problem

Drill thru roof of conduit

"

"

"

0

0

"

1534

"

1023

" Leaks not a problem

" Replacing cond. lineDry spot on rainy dayHeath good on HP, not on LPLeaks not a problem

Leaks not a problemLeaks not a problem

716

"

"

0

"

"

aFS = Feel street or vault surface; A = Acoustic; IR = Infrared.bSystem is very old, and operator indicated that no money would be expended on leak repair. Operatorhopes to expand system significantly, at which time in-line leak detection system will be installed.

"

"

8 6iR 14

24

The following is a summary of the experiences of utilities that haveused "acoustic" technologies successfully (in several cases, the devicesactually measure vibration).

" Baltimore Thermal: Heath system, bought four years ago for about$1,000. A receptor, of 3-4 in. diameter, is placed on pavementand moved 3-4 in. at a time. Have a staff person who uses thedevice effectively. Describes accuracy as within 4-5 ft. However,the company is interested in the ANL technology in order tofurther improve effectiveness.

" Cleveland Thermal: Heath system; price about $2000. Staffperson required time to develop a "good ear." Sandy soils in area;system doesn't work with clay soils. Must use between 2:00-5:00a.m., when background noise is minimal.

" Concord Steam: Use city water department's acoustic device, aHeath Aquascope. An acoustic sensor is placed directly on thepavement or in contact with a valve. Where only soil is above thepipe, a bar must be driven down to contact the pipe to obtain agood signal.

* Consolidated Edison: Sometimes uses bar-hole method, wherebar is driven down to contact the conduit. However, this is notalways possible due to obstruction by other utilities (probably30% of system). Bar-holing is also a safety concern.

" Detroit Edison: Drills hole in pavement and inserts sonic probeto contact the conduit; repeats this every foot or so in area inwhere the leak is suspected. Describes accuracy as "hit or miss."Company is interested in the ANL technology.

" Harrisburg Steam Works: Use the "STS Water Leak PinpointingInstrument" made by Paul Michael & Associates, Inc. (814-238-8533). Although Dr. Michael was reluctant to share specifics onthis vibration-measuring device, including the frequencies atwhich it operates, he did provide the information s"own inAppendix C. Dr. Michael sells his device mostly to water utilities,but Harrisburg bought one three years ago, and now several othersteam systems have bought the instrument or plan to do so.

25

Harrisburg indicated that it works well but needs a quietbackground, so it is used the night. Sets on a steel tripod on the

pavement. Dr. Michael prices the device at $3200.

" Pacific Gas and Electric: Can't remember name of maker of thedevice, but thinks it might be Heath. Works well except whenbackground noise is significant.

" Seattle Steam: Bought a device from Dr. Michael (see Harrisburgnotes) for $2600 three months ago. Works very well on directburied pipe, but is tricky with conduit.

" Trigen-Kansas City: Uses Heath Aquascope on high-pressurelines, but it does not work on low-pressure lines. Apparently,sensitivity is too low to detect leaks in the 15-psi low-pressurelines.

" Youngstown Thermal: Borrows Cleveland Thermal's acousticdevice. Works well, but requires practice to use effectively.However, the company is interested in the ANL technology inorder to further improve effectiveness.

Of thesc 10 utilities currently using acoustic technologies with somesuccess, five are interested in the ANL technology because they feel that thecurrent methods are not as effective as is desirable..

Acoustic leak location technology has been tried without success by18% of respondents. Among the potential reasons why some utilities wereable to successfully use acoustic devices while others were unsuccessful arethese: (a) technology used, (b) soil type, (c) staff experience/expertise, and(d) pipe depth. The influence of these factors on the eight utilities thatunsuccessfully tried acoustic devices was not always clear. Generally, if theequipment is no longer used the utility was not able to describe the devicein detail. However, the following notes were obtained on these experiences.

" Alabama Power: "Hand-held sonic tester."

" Boston Thermal: Apparently tried Cleveland Thermal's Heathsystem. They noted that, in contrast to the Cleveland Thermal

26

area, where the technology is used successfully, the soils inBoston are not sandy. Pipe depth is about 10 ft.

" Eugene Water and Electric Board: Unsuccessfully tried"Geophones" used by city water department, described as astethoscope placed on the pavement. Pipe is 2-15 ft. deep.

" Indianapolis Power and Light: Tried Heath technology withoutsuccess 3-4 years ago. Pipe depth varies significantly, from 2 to10 ft.

" Kent County Public Works: Tried water department acousticdevice.

" Pittsburgh Thermal: Tried acoustic leak location contractor.

* St. Louis Thermal: Borrowed and used Cleveland Thermal'sequipment, without success. Also tried a leak locationcontractor.

" Wisconsin Electric: Bought an acoustic device (no detailsavailable) about 10 years ago, but was unsuccessful with it.Needed to bar-hole down due to depth of pipe, which rangesfrom 5 to 18 ft.

While seven systems have successfully used infrared technology, six othershave tried this method but found it not effective. Pipe depth may also be asignificant factor in these differences.

4.2.2 Interest in ANL Acoustic Technology

Overall, 41% of the respondents indicated interest in using the ANLacoustic technology, while 59% indicated no interest (Table 8). Utilitiesthat were not interested were asked to explain why; some utilities gavemore than one reason. Responses are summarized below.

" Leaks are not a significant problem: 58%

" Current methods work well: 43%

" Don't want to consider using hot tap: 15%

27

Table 8. General Interest in ANL Technology

Interested in If not, why not?using ANL

technology? Leaks Current Don'tnot a method want

Name of system Yes No problem works hot tap Other

Alabama Power Company "Baltimore Thermal "Boston Thermal "Central Heat Distribution (Vancouver) " "Cleveland Thermal "Cogeneration Management Company "Concord Steam "Consolidated Edison "Dayton Power and Light " "Detroit Edison "District Energy St. Paul "Energy Networks Inc. "Energy Systems Co. - Omaha "Eugene Water and Electric Board " " "Fairbanks Municipal Utilities "Georgia Power Co. "Harrisburg Steam Works "Indianapolis Power and Light "Jamestown Board of Public Utilities " "Kent County Public Works "Lansing Board of Power and Light "Mid-America Energy Resources " "Minneapolis Energy Center "Nashville Thermal "NRG Thermal "Pacific Energy/Central Plants Inc. "Pacific Gas and Electric "PACT, Ltd. "Philadelphia Thermal " "Pittsburgh Thermal "Public Service Co. of Colorado "Rochester District Heating Cooperative " "St. Louis Thermal "Seattle Steam "Toronto District Heating Corp. " "Trenton District Energy "Trigen - Tulsa""Trigen - London, Ontario "Trigen - Kansas City "Trigen - Nassau County " "United Illuminating "Willmar Public Utilities "Wisconsin Electric 0

Youngstown Thermal "

Total 18 26 15 11 4 2

% of respondents 41 59 58 42 15 8% of respondents 41 59 58 42 15 8

28

Although only four respondents who are not interested in the ANLtechnology noted the hot tap as the reason, reservations about hot taps arepervasive and very significant. Concerns about hot taps focus on safety, cost,and introduction of additional potential leak sites.

Listed below are notes on each utility that expressed interest in theANL technology, including their thoughts on hot taps:

" Baltimore Thermal's leak problems are in low-pressure (20-35psi) lines. Key concern is minimizing labor costs.

" Boston Thermal has isolation valves at each manhole, and wouldshut off a section of line to weld in the tap rather than install ahot tap. On average, the system loses about four bellows everyyear and develops several other leaks.

" Consolidated Edison is concerned about hot taps from all threestandpoints noted above. The company bought hot-tapequipment 10 years ago, and has used it, generally for 3-6 in.taps. The equipment is too large to fit into a manhole. Based onexperience, a hot tap costs about $4000 ($3000 for theexcavation plus $1000 for the tap, assuming two men for one dayat $30/hr).

" Detroit Edison stated that cost effective, quick hot-tap servicefrom a contractor would be essential. The company does notallow its staff to do hot taps. About 40 leaks are repairedannually, at a cost of $10,000-15,000 per excavation. Annualbudget for leak work is about $1 million.

" Energy Networks Inc. noted that although leaks are not aparticular problem, some of its older steam pipe is almost 30years old; the company is interested in the ANL technology if itproves to be cost-effective.

" Indianapolis Power and Light noted that its leak problems arealmost all in the low-pressure line (10-15 psi), and that hot tapsin a low-pressure line are not a problem. (Of the 11 systemsproviding both high-and low-pressure service, 5 indicated thatthe low-pressure system is where their leak problems are. The

29

company spends about $1.25 million annually on leak detectionand repair.

" Kent County expressed reservations about hot taps. Quickrestoration of service is key.

" Lansing Board of Power and Light is concerned about corrosionpotential at hot-tap sites. Leaks do not receive a high priority atpresent.

" Minneapolis Energy Center felt that a hot tap could be done in amanhole if the leak is small enough.

" NRG Thermal's leak problems are unusual: they generally occurin a 150-psi condensate line. Because a portion of the line islocated along railroad tracks, shoring requirements makeexcavation very expensive (perhaps $25,000 per hole). Hot tapsof less than 1/2 in. do not appear to be a problem and could bedone in vaults, but cost is estimated at about $1000 per tap.

" Pacific Energy Co./Central Plants Inc. is interested in the ANLtechnology, but needs are unusual because most of its systemsare chilled water or high-temperature hot water; only a smallamount of steam service is provided.

" PACT, Ltd. is fairly successful in locating leaks, but is interestedin improvement. The company is concerned about hot taps,particularly in conined spaces.

" Pittsburgh Thermal's primary concern is leaks in its condensatelines.

" St. Louis Thermal would not buy the ANL acoustic equipment butwould be interested in contracting with a company that ownsthe equipment.

30

* Toronto District Heating Corp. has problems in locating leaks inits low-pressure (15 psi) line. As a result, the company isinterested in the ANL technology if the hot taps can be done inmanholes, so excavation would not be necessary.

" Trenton District Energy and Trigen-Tulsa are interested for thelong term, although leaks are currently not a major problem foreither company.

Most of the companies that expressed interest are looking for a mobilesystem to be implemented as needed (Table 9). Only two expressed interestin a permanent leak detection and location system.

All of the companies expressing overall interest in the ANL technologywould consider hosting a field test, depending on specifics (particularlycost).

4.2.3 European Experience

The following descriptions of European leak location practices arebased on discussions with these individuals:

" Dr. Hans Mortensen, President of the Metropolitan CopenhagenHeating Transmission Co. In addition to managing theCopenhagen system, which has 30 miles of twin pipe, Dr.Mortensen is very active in the International Energy Agency ondistrict heating matters.

" Sture Andersson, who has served as Production Manager of theMalm6 Energy Authority in Malmo, Sweden, and as Chairman ofDistrict Heating Technology at Varmeforsk, the SwedishThermal Energy Research Institute. He is currently responsiblefor Research and Development at Malm6 Energy, and isProfessor in district heating at the Institute of Technology inLund.

" Eric Peterson of A/S Bjeld & Lauridsen, a Danish company thatprovides infrared leak detection and location servicesthroughout Europe.

31

Table 9. Specific Interest in ANL Technology

Interested

Types of system in fieldoftnterst test?

Permanent MobileName of system system system Yes No

Alabama Power CompanyBaltimore Thermal " " "Boston Thermal "Central Heat Distribution (Vancouver)Cleveland ThermalCogeneration Management CompanyConcord SteamConsolidated Edison " "Dayton Power and LightDetroit Edison " "District Energy St. PaulEnergy Networks Inc. "Energy Systems Co. - OmahaEugene Water and Electric BoardFairbanks Municipal UtilitiesGeorgia Power Co.Harrisburg Steam WorksIndianapolis Power and Light "Jamestown Board of Public UtilitiesKent County Public Works " "Lansing Board of Power and Light " "Mid-America Energy ResourcesMinneapolis Energy Center "Nashville ThermalNRG Thermal " "Pacific Energy/Central Fiants Inc. " "Pacific Gas and ElectricPACT, Ltd. "0"Philadelphia ThermalPittsburgh Thermal " "Public Service Co. of ColoradoRochester District Heating CooperativeSt. Louis Thermal " "Seattle SteamToronto District Heating Corp.Trenton District Energy "Trigen - Tulsa "Trigen - London, OntarioTrigen - Kansas City "Trigen - Nassau CountyUnited IlluminatingWillmar Public UtilitiesWisconsin ElectricYoungstown Thermal

Total 2 10 18% of respondents 5 23 41

32

Electric Alarm Systems: In-line electric alarm systems generally were

installed during construction of European district heating systems afterapproximately 1975. Initially, many of these systems had significantproblems with false alarms and other malfunctions, due to poor qualitycontrol during the manufacture of prefabricated pipe sections, as well as tobad connections between pipe sections in the field. (Notably, these sametypes of problems have been visible in North American installations. Thishas resulted in considerable efforts to "debug" these systems and, in twocases, abandonment of the alarm system.) These problems have apparentlybeen solved in Europe through attention to proper workmanship, both inthe factory and in the field.

Infrared Imaging: The electric alarm systems are sometimesaugmented with infrared techniques; in older systems, infrared is theprimary leak detection and location method. Infrared images can be takenwith a camera mounted on the roof of a car or on an airplane flying at aaltitude of no more than 300 m.

Infrared imaging is best done at night when it is not raining and whenthere is no snow on the ground. Fog is also problematic. The best imagesare generally obtained in spring or fall.

The use of infrared is much more widespread in Europe than in NorthAmerica, at least in part because hot water, rather than steam, is theprimary medium of heat transmission in European DH systems. The highertemperatures in steam piping apparently result in more blurring of theinfrared image, thereby reducing its value in pinpointing the location ofleaks.

Another factor is pipe depth. Bjeld & Lauridsen has stated that theinfrared technology is useful in examining pipes no more than 2 m deep.Danish district heating pipes, for example, are normally about 1 m deep.

At the Studsvik Research Institute in Sweden, thermography is now

being further developed so that it can not only detect and locate leaks butalso quantify the extent of heat loss.

Acoustic Technologies: Almost two-thirds of the district heatingpiping in what was formerly West Germany were installed without in-line

33

electric alarm systems. To address the needs of these systems, work hasbeen done to develop an acoustic leak location technology called "Lokal."This technique is similar to that being pursued by ANL, i.e., correlationanalysis of acoustic signals from sensors placed on each side of thesuspected leak area. However, the sensors are placed on the pipe ratherthan in-stream, as has become necessary to provide accuracy in location ofleaks in steam pipes. The German work is directed toward hot water pipes.The development of "Lokal" was undertaken under the auspices of the IEAduring 1984-87, and an IEA report was published.

Dyes: One more technique being developed for leak detection is theintroduction of a dye into DH water. Although the purposes of this technique(detecting leaks into building domestic hot water or into the buildingsubstation) are different than that of the leak detection technology beingdeveloped by ANL, it is described here as a matter of interest.

In Sweden, only a single-wall heat exchanger separates district hotwater from the domestic hot water supply for the buildings served. As aresult, considerable attention is paid to preventing leaks from the districtsystem into the domestic hot water supply. To address this issue, testswere conducted with a dye called pyranine. The results were encouraging,and even small leaks could be detected.

4.i Conclusions from Survey

1. The extent to which leak detection is important varies considerablyfrom utility to utility.

" At least three of the larger utilities spend $1 million or more eachyear locating and repairing leaks.

" One-half of the respondents do not consider leaks to be a problemand/or are satisfied with current leak location methods.

- More than one-third (34%) of the respondents do not considerleaks a significant problem.

- One quarter of the respondents are satisfied with their currentmethods for locating leaks. Within this group, 9% also indicatedthat leaks are not a problem.

34

2. The most common leak location method is decidedly "low-tech":feeling the pavement to see where it is hottest and/or zeroing in on specifictrouble-spot components using as-built drawings.

3. Almost one-quarter (23%) of the respondents have found an acoustictechnology useful to some extent in leak location, while 18% have tried anacoustic technology without success.

" A particular acoustic technology that has been used with goodsuccess by one utility may be totally ineffective for another.

" The effectiveness of various acoustic or vibration-sensing devicesappears to depend on a variety of factors, including the particularacoustic device used, staff expertise/experience, soil type, and pipedepth.

" Existing acoustic technologies are relatively inexpensive (severalthousands of dollars).

* One-half of the respondents that found an existing acoustic technologyuseful also stated that they are interested in the ANL technologybecause their current methods are not as effective as desirable.

4. There is significant interest in the ANL technology, particularly amongthe larger steam utilities.

" More than 40% of the utilities surveyed are interested in using theacoustic leak detection and location technology being developed byANL.

" The utilities interested in the ANL technology represent 76% of thetotal thermal energy sales by the surveyed utilities for which sales datawere available.

" Of the utilities that expressed an interest in the ANL technology, 28%do not feel that leak detection is a high-priority problem.

35

" Of the utilities expressing no interest in the ANL technology, thefollowing reasons were cited: leaks are not a problem (58%); current

methods work well (42%); don't want to do hot taps (15%).

5. The market for the ANL technology is likely to be limited to arelatively few large steam systems.

" The likely capital cost of the ANL technology ($40,000-50,000,according to ANL) is very high relative to other leak locationtechnologies.

" However, this cost could be quickly recouped (due to the high cost ofexcavation) by utilities with a significant number of leaks and for whomthe existing acoustic or other technologies do not work.

6. Most utilities are reluctant to do hot taps, and this presents asignificant potential barrier to the use of the ANL technology.

" Concern about hot taps appears to be based on prior experience withlarge (several-inch) hot taps.

" Concerns about hot taps include safety, cost, and introduction ofadditional potential leak sites.

" To minimize overall operational costs of the ANL technology, it isimportant that the hot tap be performed in a manhole.

" The safety and cost problems with the size of tap likely required withthe ANL technology (1/2 in. or less) should be considerably reducedcompared to larger hot taps; this must be confirmed, quantified, anddemonstrated.

5 Acoustic Leak Location by Cross-Correlation Analysis

A few examples of leak location by cross-correlation analysis ofacoustic signals generated by a leak are presented ,o illustrate the potentialfor success and also the problems associated wigr this technology.

3 6

5.1 Leak Location with a Commercially Available Correlator at theANL Steam Leak Facility

Using leaks generated in the ANL steam leak facility,1 we evaluated aMetravib leak locator. In the Metravib system, accelerometers transmitsignals to a central processing unit via radio waves. The Metravib unit hasfixed-frequency windows; those evaluated were 400-1450, 400-2200, and400-3000 Hz. Correlation peaks from the Metravib unit were observed withsensors located 6.4 and 12.8 m from the leak. Steam pressures in the rangeof 40-70 psi were used. The window of 400-3000 Hz was optimal for theMetravib system. With the two lower-frequency windows, no correlationpeak associated with the leak was observed. One observed peak was due tonoise in the system, which is easily filtered by using a frequency windowwhose lower limitis higher. While such filtering is not possible with theMetravib system, it is with the ANL instrumentation. Another correlationpeak showed a 9-ms differential, indicating a leak-to-sensor spacing of about10 m, if the empirically determined velocity of sound of 1100 m/s is used.This result is consistent with the actual 12.8-m sensor-to-leak spacing, butthe error is large (about 30%).

The commercially available Metravib system is comparable in somerespects to the ANL system but has limitations in several areas when used tolocate steam leaks. The low- and high-frequency ranges should be moreflexible to allow use of frequency windows such as 1-2, 2-4, and 3-6 kHz.The current Metravib system does not filter noise that the ANL system can;moreover, it requires a higher sampling rate and more sampling points.The Metravib system should also present the frequency spectrum for bettercharacterization of noise sources, and it should have sensors that cantolerate steam pipe temperatures to allow direct contact with hot pipes.

5.2 Leak Location with a Commercially Available Correlatorunder Field Conditions

On September 20, 1991, personnel from Earl Ruble and Associates(Duluth, Minnesota) used a cross-correlation technique in attempting tolocate three leaks in a Northern States Power (NPS) district heating system.These leaks were in pipes filled with hot water (condensate return line,240*F, 150-200 psi). In the technique used, an acoustic sensor (withfrequency response ranging from 100 Hz-2 kHz) was placed on one end of

37

each of two waveguides. The other ends of the waveguides are put incontact with the pipe in two different manholes on either side of thesuspected leak. Cables carried the electrical signals to the instrumentationfor the location analysis. The first leak could be heard at two manholes 391ft apart. However, no correlation peaks were evident that could be used toaccurately locate the leak.

In past field studies, Ruble and Associates have discovered thatpipelines in air (not buried), such as those suspended on wall brackets in abelow-ground room, tend to "ring." They believe that this is because asound wave traveling along the water causes the pipe to vibrate in anextremely minute manner, creating sound waves that are in the samefrequency ranges as true leaks. In this case, the leak sound was extremelystrong and it could have induced the pipe vibration that is described asringing. This ringing could overwhelm the leak sound and prevent asuccessful cross-correlation analysis. Without the damping effect ofsurrounding soil or sand, ringing can occur in varying degrees, dependingon all the factors at a particular location. In the case of the NSP condensatereturn line, the pipe is encased in a very-low-density insulating materialdesigned to prevent heat loss but not to support a pipe securely. In such asituation, there is no known method of correlating a leak if the conditionsare adequate to cause the ringing.

The second field trial was at a location said to be between transducerlocations 600 ft apart. The second pipeline is constructed just like the onedescribed above. A weak leak sound was detected, but the correlation wasvirtually ideal. The signal-to-noise ratio was good and the leak location wasspecific. However it placed the leak at the "east" transducer. This means theleak was at that point or at a location farther away along the pipeline. Fromprevious experience with this situation, the leak was either at thetransducer location or was out of span (not between sensors) somewherefarther east of the "east" transducer location because there is no branch offthe condensate line. The test equipment was rearranged so that thepresumed leak would lie between the old east transducer and the newtransducer farther east. Again, an excellent leak pattern was obtained onthe monitor. In this case, the leak was indicated to be 19 ft west of what isnow referred to as the new east transducer location. This was perplexingbecause that is where an excavation had been made a week earlier to repaira leak. Excavation later revealed that the source of the noise was indeed a

38

leak from a temporary clamp about 19 ft from the transducer location, aspredicted. The leak rate was very small, also as predicted.

A question that must be answered is why it was possible to obtain agood correlator pattern on the monitor screen in the second case and not inthe first. At present, we believe that the insulation in contact with the pipeprovides enough damping to reduce the ringing and permit the leak soundto predominate in the second case (smaller leak). It is possible that thehigh pressures are important factors here as well.

At the third location, a strong leak was detected. However, pumpsfrom a paper mill about 1200 ft away caused interfering sounds and acorrelation analysis was not possible.

5.3 Leak Location with a Research-Quality Correlator underLaboratory and Field Conditions

Laboratory tests were carried out at ANL with artificial leaks underconditions that simulate the temperature and pressure of a steamdistribution system (180 psi, 350 F). Laboratory-quality instrumentation(Spectral Dynamics Signal Analyzer SD375, Khrone-Hite filters. andTektronix AM502 amplifiers) were employed. Laboratory testing wassuccessful when sensors were placed directly on the pipe outer wall. Fieldtests with this system indicated that, in many situations, steam leaks inunderground piping system can be located by acoustic techniques. However,application of the tested technology to underground piping is subject tolimitations, chief of which is the presence of bellows that severely attenuatethe acoustic wave generated by the leak. Where two acoustic sensors can beplaced on bare pipe on either side of a leak, with no bellows intervening, itis possible to detect and locate a leak by cross-correlation analysis. Wheremanholes are separated 200 ft or more, it should be possible to detectsteam leaks with sensors placed on the pipe outer wall if the leak is large(i.e., significant vapor is visible at one or both manholes).

5.4 Leak Location with an In-Stream Sensor

Transducers or transducer/waveguide systems placed directly on the

steam pipe outer wall may not be effective enough to locate leaks in longruns of DH piping or in runs with bellows between sensors. One possibility

39

for circumventing the general problem of steam leak detection withexternally mounted sensors is to insert an acoustic transducer inside thepipe to detect steam-propagated sound waves directly. The main purpose ofthe program being carried out at ANL in collaboration with NRG Thermal

and Consolidated Edison is to develop an in-stream sensor for steam leaklocation.

We have carried out a brief evaluation of in-stream monitoring using acapacitance microphone to illustrate the potential for improvements inlocation capability. Cross-correlation analysis of signals from a gas leak inthe ANL piping system suggests that in-stream monitors are more effectivethan sensors mounted on the pipe outer surface. The use of commerciallyavailable capacitance microphones or miniature hydrophones (e.g., bruel andKjaer model 8103) may not be viable for detection of steam-propagatedsound because of the elevated temperature of the steam. Special high-temperature microphones (e.g., Endevco models 2510 or 8521-5M 1) aredesigned for high-intensity applications (e.g., jet engine noise) and may notbe sensitive enough for detection and location of steam leaks. The mostpromising sensor is one made of a piezoelectric material fixed in a tubeabout 1/2 in. in diameter and able to tolerate the elevated temperatures andpressures of a steam system. Such high-temperature microphones can beinserted without disturbing service, by means of a hot tap.

6 Conclusions

Several leak detection techniques are currently available for districtheating and cooling systems. Application and effectiveness of eachtechnique depend on the design and installation method of the DHC piping,location of the leak (in the jacket or the carrier pipe), system operatingparameters, and knowledge of system layout and components. The mostcommon systems used today are classified according to their principle ofoperation as follows: acoustic emission, infrared spectroscopy, tracer gas,and electrical.

While all of these techniques have been tried in one form or another,only acoustic leak detection has the potential for being the most effective forlocating leaks. However, sensors placed directly on the pipe outer wall maynot be effective enough for acoustical location of steam leaks in long runs ofDHC piping. One way to circumvent the general problem of steam leak

40

detection in buried pipe is to insert an acoustic transducer inside the pipeto detect steam-propagated sound waves directly.

A survey was undertaken as part of a joint program between the U.SDepartment of Energy and utilities involved with district heating andcooling. The purpose of the survey is to identify and characterize currentpractices for detecting and locating leaks in district heating systems;specifically steam systems. This information reflects district heatingindustry conditions, needs, and requirements and will assist ANL in thedevelopment of acoustic leak detection technology

Acknowledgments

The authors wish to thank M. Spurr for the survey data and W.Lawrence, R. Popper, and R. Carlson for their contributions to this project.

41

References

1. D. S. Kupperman and D. E. Karvelas, Acoustic Leak Detection forDistrict Heating Systems, Argonne National Laboratory ReportANL-87-60 (Feb. 1988).

2. K. E. Cooper, C. Marsh, and E. G. Segan, Evaluation of Techniques forLocating Leaks in Underground Heat Distribution Systems, U.S. ArmyCorps of Engineers, Construction Engineering Research LaboratoryTechnical Report M-86/16 (Aug. 1986).

3. D. S. Kupperman, T. N. Claytor, T. Mathieson, and D. Prine, LeakDetection Technology for Reactor Primary Systems, Nucl. Safety,28:191 (April-June 1987).

4. J. Reason, Acoustic Leak Detection Provides Early Warning of PipingFailure, Power, 63 (Sept. 1987).

5. J. E. Coulter, T. P. Sherlock, and D. M. Stevens, Acoustic EmissionMonitoring of Cracks in Fossil Fuel Boilers, Electric Power ResearchInstitute Report EPRI CS-5264 (July 1987).

6. J. G. Dimmick and J. M. Cobb, Ultrasonic Detection Cuts ValveMaintenance Costs, Power Eng. 35 (Aug. 1986).

7. D. 0. Harris, R. G. Brown, D. Dedhis, and D. E. Leaver, AcousticEmission Leak Detection and Location Systems Technology Review,Electric Power Research Institute Report EPRI NP-80-7-LD (Dec.1980).

8. H. V. Fuchs, W. Frommhold, R. Poggemann, R. and P. Zenker,Acoustic Leak Location on District Heating Pipes, HLH, Heizung,Luftung, Klimatechnik, Haustechnik, 42:1; Fraunhofer-Institut furBauphysik, Stuttgart, and Energieversorgung Oberhausen AG, WestGermany.

9. H. Schwarze, Computer-aided Measuring System for AutomaticMonitoring of Pipe Networks and Leak Detection, TechnischesMessen, 55(7-8): 279-285; Fachhochschule Bielfeld, Bielfeld, WestGermany (1988).

42

10. H. J. Micheel, Leakage Monitoring in Synthetic Jacket Pipes forDistrict Heating Supply, Fernwaerme International, 16(6):380-385, Salzgitter Elektronik GmbH, Kiel, West Germany(Nov-Dec 1987).

11. D. B. Chang, B. M. Pierce and I. Shih, Environmental MonitoringTechnologies, SAE Technical Paper Series 910190, InternationalCongress and Exposition, Detroit, Feb. 25-March 1, 1991.

12. H. Turtiainen, Leak Location in District Heating Networks UsingAcoustical Correlation Techniques, Valtion TeknillinenTutkimuskeskus, Espoo, Finland (1982).

13. H. Gransell and J. Ljungquist, In Situ Control of District HeatingNetworks, Annual Conference of the Int'l District Heating Assoc.,(1985).

14. A. Jette, M. Norman, S. Michael, J. C. Murphy, and J. G. Parker,Active Acoustic Detection of Leaks in Underground Natural GasDistribution Lines, Materials Evaluation, 35(10): 90-96, 99(Oct. 1977).

15. A. C. Eapen, R. L. Amera, S. M. Agashe, Pipeline Leak Location UsingRadiotracer Technique, Bhabha Atomic Research Centre, IsotopeDiv.. Bombay, India (1983).

43

Appendix A:

Survey Form and Introductory Remarks forAcoustic Leak Detection and Location

44

45

Introduction to Survey

Argonne National Laboratory, under contract to the U.S. Department ofEnergy and several district heating utilities, is developing a system fordetecting and locating district steam piping leaks using acoustic technology.

The objective of the project is to develop a highly accurate acousticleak detection and location system so that excavation for repairs can beminimized. Based on previous work, it appears that for steam districtheating an in-stream sensor, probably using a hot tap, will be required toachieve the desired accuracy (within several meters).

The system would involve the insertion of two transducers into the hottaps, without disrupting steam service. Transducers could be attachedpermanently, to be periodically monitored, or a pair of transducers, as partof a mobile unit, could be placed as needed at sites of interest. Signals fromthe transducers would be transmitted by wire or radio waves and would beprocessed by mobile computer equipment.

Argonne is now performing research necessary for development of afield-implementable prototype system. On behalf of Argonne, I'd like to talkwith you about leak detection and location practices and experiences in yoursystem so that the prototype system is developed with a full understandingof district heating industry needs and requirements.

46

LEAK DETECTION SURVEY

Name of System

Contact Name

Phone

&a. Distribution yStem

1. Year oldest pipe installed

3. Type of pipe installation

Box conduitSolid pour conduitTunnelPrefab conduitDirect BurialOther

5. Intervals between expansion devices

6. Condensate return? yes

7. Intervals between manholes

8. Temperature and pressure

2. Miles of pipe

4. Expansion devices

Slip jointsBellowsBall jointExp. loopOther

feet

no

feet

rFF

psi (HP steam)psi (LP steam)psi (hot water)

B. Current Leak Detection

1. What types/locations of leaks are your biggest problem?

ValvesFlanges Expansion devicesOther

2. How are leaks detected now?

Rollers WeldsExternal corrosion

3. How are leaks located?

-1

47

4. What is the accuracy of your location methods?

C U a of Acoustic System

1. Would you be interested in using an acoustic system asdescribed earlier? yes _ no

2. If not, why not?

3. What would increase this system's usefulness to you?

4. Are you interested in:

a. Ongoing system for monitoring, detection andlocation

b. A system for use as necessary to locate leaksdetected through other means

5. Would you be interested in field testing a prototypesystem? yes no

48

49

Appendix B:

Notes From Survey

50

Name of System

Contact Name

Phone

51

LEAI DETECTION SURVEY

~/e t'^A5..b e,%,.0 1/0

arm yw- M --- ewoo

8. Temperature and pressure 3 -37o FFF

/5~a psipsipsi

(HP steam)(LP steam)(hot water)



Valves Rollers

Welds Flanges

Expansion devices External corrosionOther -73rp_

A. Distribution System

1. Year oldest pipe installed fc6 2. Miles of pipe _

3. Type of pipe installation 4. Expansion'devices

Box conduit _______ Slip jointsSolid pour conduit Bellows n a v-rTunnel Ball jointPrefab conduit .-- ajcot _Exp._loop

Direct Burial Other

Other

3--c' yw.

5. Intervals between expansion devices ___feet

6. Condensate return? yes _______ no

7. Intervals between manholes 'YD feet

52



V7/ 404A, c74 1 .57 r / /c


C. Use of Acoustic System

1. Would you be interested in using an aco ic system asdescribed earlier? yes ___no

2. If not, why not?



a. Ongoing system for monitoring, detection and locationb. A system for use as necessary to locate leaks detected

through other means

5. Would you be intereted in field testing a prototype system?

yes no

cs\leaksurv

53

N

pi

A

1

3

LEAX DETECTION SURVEY

are of System 9 dM .,e

contact Name ir/ a S6 'v /Ayr , A_2Jdn A

hone __ /__________

. Distribution System

. Year oldest pipe installed 2. Miles of pipe /.

. Type of pipe installation 4. Expansion devices

Box conduit & ____Slip joints 'Solid pour conduit Bellows ______

Tunnel Ball joint

Prefab conduit Exp. loop -oDirect Burial Other

Other

5. Intervals between expansion devices ^-ago feet

6. Condensate return? yes no

7. Intervals between manholes as ~ feet - ,36-47 /L4CX / 5 7

8. Temperature and pressure 37S F /bo-/r psi (HP steam).7o F ao-3r psi (LP steam)

F psi (hot water)


1. What types/locations of leaks are

ValvesWeldsExpansion devicesOther . Svey 7 T

your biggest problem?

RollersFlangesExternal corrosion

~

54


1/;VA 09,, a o(- QL 4,0

3. How are leaks located? 7 - A

4i -ak JY 6, 4o %'-ae4. What is the accuracy of yo~r location methods?


1. Would you be interested P using an acoustic system asdescribed earlier? yes no

2. If not, why not?


Aljn1 4G G4w- cc17


Ongoing system for monitoring, detection and locationA system for use as necessary to locate leaks detectedthrough other means

5. Would you be interested in field testing a prototype -system?

yes no

cms\leaksurv

55

(


lame of System i 9 / Air EAM

Contact Name 2h4 /2i, 4e/

Phone 5-A -- /g'ado


1. Year oldest pipe installed /9c 2. Miles of pipe

3. Type of pipe installation 4. Expansion devices

Box conduit ___-__ Slip jointsSolid pour conduit Bellows(T/BloTunnel Ball__on

Prefab conduit alta_ _Exp._loop

Direct Burial OtherOther

-7 -f -rrx er t OU740

5. Intervals between expansion devices _____feet


7. Intervals between manholes '/D feet

8. Temperature and pressure 3d 37o F

__-__ FF

/So psipsipsi




Valves Rollers

Welds FlangesExpansion devices External corrosionOther - _7___

V?4 Or 7/9 -amne_ G~j m.

r/;. w

56





1. Would you be interested in using an acoyic system asdescribed earlier? yes _ no

2. If not, why not?




through other means

5. Would you be intereed in field testing a prototype system?

yes no

cus\leaksurv

57

N

C

P

A

1

3

LEAF DETECTION SURVEY

ame of System 6ods';A ZZ2 ../

ontact Name 4.,, /v7c, r -- ///' >r

hone 1/2- 6 fo-{ O


. Year oldest pipe installed /140 2. Miles of pipe S


Box conduit Slip jointsSolid pour conduit BellowsTunnel Ball joint

Prefab conduit Exp. loopDirect Burial OtherOther

'/2 ' e(r

L

64' ~lve

// 5-Q ce44 .f -- '-r'- 4-, --

5. Intervals between expansion devices 25~ feet

6. Condensate return? __ yesno

7. Intervals between manholes 9 F S feet

8. Temperature and pressure F____ F, psi (HP steam) ,4 aF psi (LP steam)F psi (hot water)



Valves Rollers

Welds FlangesExpansion devices y () External corrosionOther

58

2. How are leaks detected now? /4 V A e. 6


t/ w dr wa, j pi'

7I A4;%,IA)



1. Would you be interested in ing an acoustic system asdescribed earlier? yes no

2. If not, why not?



a. Ongoing system for monitoring, detection and locationA system for use as necessary to locate leaks detectedthrough other means

5. Wouldou be interested in field testing a prototype system?

yes no

cms\leaksurv

59

N

C

PI

A

1

3


ame of System -VI/ 4' rL 4#i - V4x ev, 4

ontact Name 1/r ', c ;

hone now6J'9' fASS


. Year oldest pipe installed /96g 2. Miles of pipe


Box conduit Slip joints t jSolid pour conduit BellowsTunnel Ball jointPrefab conduit Exp. loopDirect Burial _/ _Other

Other ___lev

ke44v f . s4 arf' y1

Intervals between expansi devices

Condensate return? V yes

Intervals between manholes fe

feet

no

et

8. Temperature and pressure 3 SO FFF

/?tr/opsipsipsi




Valves RollersWeldsFlangesExpansion devices External corrosionOther

''4

5.

6.

7.

60





1. Would you be interested in using an acojtic system asdescribed earlier? yes no

2. If not, why not?



a.b.

ongoing system for monitoring, detection and locationA system for use as necessary to locate leaks detectedthrough other means

5. Would you be interested in field testing a prototype system?

yes no

cms\leaksurv

61

Name of System

Contact Name

Phone


/ 1W -- ,S7f era / , /

2.

4.

Miles of pipe AExpansion devices

Slip joints V/ //IBellows _/_Vn__ -r_''

Ball joint

Exp. loop

Other

,4- t P yI i4 )




Box conduit 6va Z i' 7Solid pour conduit v7TunnelPrefab conduit 9/ k/ad/ -wDirect Burial

Other

5. Intervals between expansion devic


7. Intervals between manholes' /o4

8. Temperature and pressure 36,' F26o F

F

/5-D psiO -a psi

psi




ValvesWeldsExpansion devicesOther


Rollers

FlangesExternal corrosion ~.-

,la7

:es oo feet p f sL 3

no

feet 'WoAI*&i jV A 4 / '.

62


3. How are leaks located? -_

dac" I 4 S _r4- ~rr



1. Would you be interested in using an rustic system asdescribed earlier? yes no

2. If not, why not?




through other means


yes no

cms\leaksurv

63

Name of System

Contact Name

Phone

A. Distributi


2f - 7 3. 4a-/i0f- 6;.

on System

Year oldest pipe installed e'9t 2. Miles of pipe /XType of pipe installation 4. Expansion devices

Box conduit Slip jointsSolid pour conduit BellowsTunnel Ball joint

Prefab conduit Exp. loopDirect Burial OtherOther

Inev s 4tewAen exansinkevees fet

Intervals between expansion devices feet

1.

3.

5.

6.

7.

no

et

8. Temperature and pressure_ F _ /aV psi (HP steam)F ___psi (LP steam)Fspsi (hot water)

B. Current Leak Detection G w


Valves RollersWelds Flanges

Expansion devices External corrosionOther

Condensate return? yes


m 4b - - - - - - - - - - - - - - - - - - -- ,

.

64





1. Would you be interested in usingdescribed earlier? yes

an acoustic system asno

2. If not, why not?



a.b.



yes no

cms\leaksurv

Name of System

Contact Name

Phone

65

LEAE DETECTION SURVEY

0O- s - /6

f//

5...-.


. Year oldest pipe installed /4Jofr

. Type of pipe installation


6hV'404 /I 9oZ Atj 6 e

5.

6.

7.

2.

4.

Miles of pipeA"

Expansion devices

Slip jointsBellows -Ball jointExp. loopOther

4

jV /AJS.' 441ft L -m

Intervals between expansion devices feet A-#

Condensate return? yes no

Intervals between manholes _ feet A,, w

8. Temperature and pressure 37' FFF



ValvesWelds P/e.Expansion devices 1/Other

/lr psipsipsi



Rollers

FlangesExternal corrosion

A

1

3

.

. L

r ! I L!

66


1Id 4 V1 t,,off-' dLd r rLer* fJobd#-

AOno. r k

fV e *j 4

6e,4 sv& an 4


4. What is the accuracy of your location metho s.


1. Would you be interested in using an acoustic system asdescribed earlier? yes no

2. If not, why not?




through other means


yes no

cms \leaksurv G ' 6 o

0' D6

ow#

Vvr-"6p3

67

Name of System

Contact Name

Phone


0 a - d/ / o

7 ~pi~ e...a'

9/a-~ 9




Box conduit

Solid pour conduitTunnelpggsercrnduitDirect BurialOther

&Opc-

2. Miles of pipe


Slip jointsBellows ,Ball joint t_ .Exp. loop fOther

PI5Th/1cv -- --- 4s7(**lO ,

5. Intervals between expansion devices_ feet


7. Intervals between manholes 3i7/) feet 4. 06 e, f//y



FFF

Ja Opsipsipsi





>4r 040,0; ;f

68

2. How are leaks detected now? U / Jp 4 &e



C. Use of Acousti~c System

1. Would you be interested i sing an acoustic system asdescribed earlier? Lyes no

2. If not, why not? -A/"or >4 NI

v 71e r63 4 .vh*#t. 7%ro 770. ~d/,s ^ "-o


4. Are you interested in: /e4 /.


through other means


yes no

cms

; k4/4.v / 4 r oi M

\leaks(rA4-' a%

}A 2O /A,,.)

69

N

C

PI

A

1

3


ame of System %P4y5 Fn.i' ' 6Z4

ontact Name i -r /odi', I

hone 5/3 - >2-e /


. Year oldest pipe installed /1OL 2. M

. Type of pipe installation 4. E

Box conduit '' /-/5 . SSolid pour conduit ?o 7o'.X BTunnel BPrefab conduit EDirect Burial 0Other t&V/ie -71;

iles of pipe /

xpans ion devices

lip jointsellowsall jointxp. loopthere

5. Intervals between expansion devices feet


7. Intervals between manholes Lu _ feet

3.7 lf / pr (/ Psv 4%)8. Temperature and pressure 3 L F /fo psi (HP steam)

F ? psi (LP steam) & 'cAro-F __ psi (hot water)



Valves Rollers

Welds FlangesExpansion devices External corrosion .----Other

1W 4 "-

/7~4e A ~ ~e~1 ,. 'U

'o / $ 1d44x y ma

'Oeo

F

v / p

70





1. Would you be interested in using an acoustic system asdescribed earlier? _ yes -- no

2. If not, why not?




through other means


yes no

cms\leaksurv

71

Name of System

Contact Name

Phone

LEK DETECTION SURVEY

~~ &.4Md/


1. Year oldest pipe installed d


k16t Box conduit

A:et Solid pour conduit ,/

TunnelPrefab conduitDirect Burial

Other

2.

4.

Miles of pipe S-dExpansion devices

Slip joints </Bellows

Ball joint

Exp. loopOther

J) o1/4

5. Intervals between expansion devices /Oo-rdsfeet

6. Condensate return? yes L' no x 4'p9 s - 5~'4

7. Intervals between manholes Y4-5N feet A,8. Temperature and pressure 39-3 F /a-I/)r psi (HP steam)

7-=1 F yo- o psi (LP steam)F ___psi (hot water)




Expansion devices j/ External corrosion OtrerOther

Fx a/o " 5 k s

fg ~ de 0/ --/ -- i

p

0

4

72

2. How are leaks detected now? /dsi/ ' '*,.




1. Would you be interested in sing an acoustic system asdescribed earlier? yes no

2. If not, why not?


aVG?' ' zvc 9 /,v'L p Sr~ 4 4' v



5. Would ou be interested in field testing a prototype system?

yes no

cms\leaksurv

73

Name of System

Contact Name

Phone

A. Distribute


/c72 - f f

Year oldest pipe installed /.S3

Type of pipe installation

Box conduitSolid pour conduitTunnelPrefab conduitDirect Burial

Other

2. Miles of pipe d204. Expansion devices

Slip joints

Bellows _ _

Ball jointExp. loopOther

Intervals between expansion devices feet .


Intervals between manholesA) 3SO feet v*wr

8. Temperature and pressure ____ F ____ psiF psi

pyl ot Asg , a3D4/ p F /0+!,Aso psi



%=. c'

What types/locations of leaks are your biggest problem?

Valves Rollers ____

Welds FlangesExpansion devices External corrosionOther

1.

3.

5.

6.

7.

1.

on System

I lw W At - Alk 4 W ~ MW mm 40 V& 4ar "W w lmw MMM my 1111C"w 4 0AL

74


/e.az4nq I/tO

Q m may~iA # Ap 9. 6~r O~%m;)




1. Would you be interested in using an ac9 stic system asdescribed earlier? yes no

2. If not, why noti-'A~' 6op 4A y



a.b.



yes no

cms\leaksurv

-ry.rW., 4'e# 11A,4

75

Name of System

Contact Name

Phone


o.,-~; t / - Ao7


. Year oldest pipe installed / A


Box conduitSolid pour conduitTunnel

Prefab conduitDirect BurialOther

SP44e~v tk ' e'W

Soy.- VO

5.

6.

7.

2.

4.

Miles of pipe

Expansion devices

Slip joints v/a.,Bellows~ - 4Ball joint ii4Exp. loop .Other -b'fI

h 4 Ovce .



Intervals between manholes --/'> feet

8. Temperature and pressure_ F s/S"0 psiF psi

/P.:-0 F psi



1. What types/locations of leaks


are your biggest problem?

Rollers


A

1.

3

-

4

76




C. Useof Acoustic!jytem


2. If not, why not? /i, -,f-




through other means


Vyes no '4 / /.4 vLw e 4,/

cms\leaksurv

77


Name of System 59fCr,& sV --6 y/4

Contact Name ZLt . v/..vj

Phone Y01'- .'96--9 o 6'


1. Year oldest pipe installed /96 ~ 2. Miles of pipe


Box conduit V e Slip joints __97-5

Solid pour conduit BellowsTunnel Ball joint /PY 5Prefab conduit Exp. loopDirect Burial Other

Other

F / h v s! , p1 0c v 'j

G 3 0N 44M, A o rrde4,

5.

6.

7.



Intervals between manholes co -Jo o feet

8. Temperature and pressure '/00 FFF

/d- psi

psipsi


n Zen ,4. z,"10B. Current Leak Detection ,w""nv' i


Valves Rollers _


4 AiA4e,

/t,+ s rc/ ,

78


v6r442 JAS oo

3. How are leaks located? / ' ,m ob oeA; a --- face w

4. What is the accuracy of your location methods? B , &'

C. Use of Acoustic System ?4 i/7

1. Would you be interested in using an acoustic system asdescribed earlier? yes _. no

2 . I f n o t , w h y n o t ?/ 4 / p h,




through other means


yes no

cms\leaksurv

79


of System Ae / 2 $

:act Name i.6

distribution System

Name

Cont

Phor

1.

3.

/ f// 2.

4.

Miles of pipe -'S

Expansion devices

Slip joints ''

BellowsBall jointExp. loop _____

Other____

2 o 'foeo, A k- 1zX&4~ 1 r4

5. Intervals between expansion devices S'o/00feet

6. Condensate return? yes no AP'ft7. Intervals between manholes 3'--ysofeet

8. Temperature and pressure 5__o_ F _ psi (HP steam)2o F * c psi (LP steam)

F _____ psi (hot water)



ValvesWeldsExpansion devices

4wzdw4O / /


Rollers


40 poe44 Z004 % W vr.

Year oldest pipe installed


Box conduit _

Solid pour conduit /'TunnelPrefab conduitDirect Burial

~y~er

A

.i ia./ 4yiVi" %F 7 r7vI%* Mi.beak-q-l

80



f- 2 dc'/ ro / rP .rti sc




2. If not, why not?




through other means


yes no

cms\leaksurv

81

Name of System

Contact Name

Phone

LEIK DETECTION SURVEY

9o'S Y59- 6.'S9


. Year oldest pipe installed 2.

. Type of pipe installation 4.

Box conduit ~ S , saySolid pour conduitTunnelPrefab conduitDirect Burial ____-_

Other 1 ,

Intervals between expansion devices



Miles of pipe

Expansion devices

Slip joints VBellows _/

Ball jointExp. loop Vi

Other

feet

no

et

8. Temperature and pressure F3S TDF

psipsi

Jo psi






Rollers


aZ4 a A A,, '' 4 4GoIw

A

1

3

5.

6.

7.

82


As" ', - -,jA'S4 e ,. o f"t w i~z G




1. Would you be interested in using an acdstic system asdescribed earlier? yes no

2. If not, why not?




through other means


yes no

cms\leaksurv

83

Name of System

Contact Name

LEA DETECTION SURVEY

114

yo y-- p g-y6-78Phone


1. Year oldest pipe installed /i 7


Box conduitSolid pour conduitTunnelPP.aeet-conduitDirect BurialOther

2. Miles of pipe 5"--



epo m e4



7. Intervals between manholes _____

8. Temperature and pressure 33o FFF

/0 & feet

no

feet t/LvA b'sV, .-/A ;l

® psi/0 psi

psi






f/

,000

84






2. If not, why not?




through other means


yes

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Name

Cont

Phor

AL

85

Lial DETECTION SURVEY

of System /4) *v (J$'zm, rilo

:act Name

he _ _ _ _ _ _ _ _ _ _ _ _ _ __t

Distribhtin Svmt.u

1.

3.

5.

6.

7.

8.

Year oldest pipe installed 2. Miles

Type of pipe installation 4. Expand

lox conduit ____Slip

Solid pour conduit Bllo_Tunnel BallPrefab conduit Exp.Direct Burial OtherOther

3f-/oh 7 4440y2

of pipe

sion devices

jointsWs /joint

loop

Intervals between expansion devices /d O feet


Intervals between manholes 200 feet

Temperature and pressure F / psi (HP steam) off<A____ F psi (LP steam)

F __,_psi (hot water)

B. current Leak Detection


Valves RollersWelds FlangesExpansion devices lExternalcorrosionOther

%w UK ---- MdrAL M lop.Ma V - A. Y A

86

2. How are leaks detected now? k6M,/zew dd44 o4 I"1 7f




1. Would you be interested in using an ac tic system asdescribed earlier? yes no

2. If not, why not?




through other means


yes no

cms\leaksurv

87


Name of System pdg, y//.Y 1. S/ -

Contact Name/,.:

Phone f/7-y(/- !T9'


1. Year oldest pipe installed 2. Miles of pipe


Box conduit Slip joints -Solid pour conduit --- Ah I /f BellowsTunnel Ball joint

Prefab conduit Exp. loopDirect Burial Other

Other

5. Intervals between expansion devices /X2-3 feet v'u"G4 '


7. Intervals between manholes /o-o"ofeet

8. Temperature and pressure _ o F psi (HP steam).yo -arF psi (LP steam)

F _ psi (hot water)



Valves RollersWelds FlangesExpansion devices External corrosion .oother

6P /'&4

p

88





1. Would you be interested in using an acoustic system asdescribed earlier? ~_yes no

2. Ifhot, wud inrA is syste' s




through other means


yes ___no

cms\leaksurv

89

Name of System

Contact Name

Phone

A. Distributi

LUas DETECTION EURVET

7/-- rtd3 -76-

on System

Year oldest pipe installed /fs"


Box conduitSolid pTunnelPrefabDirectOther

/Apv-

2.

4.

Hies of pipe.4

Expansion devices

Slip pointsour conduit Bellows

Ball jointconduit ____Exp. loopburial Other

MP% ayVC. (14 (5) /C nu& -pg

e, ev.

Intervals between expansion devices ____


Intervals between manholes feet

feet

no

8. Temperature and pressure ____ F ____ psiF psi

/f4'-fD F /oo-/yo psi




Valves RollersWelds FlangesExpansion devices External corrosionOther

1.

3.

5.

6.

7.

90


7% ire Gl Vnv .S' i - 4/n' 4 ,




1. Would you be interested in using an ac stic system asdescribed earlier? yes no

2. If not, why not?




through other means


yes __no

cms\leaksurv

Name of System

Contact Name

Phone

A. Distributic

91

LEIK DETECTION SURVEY

6 / 67 A/

$Z ~ )~ l ('t

System

1.

3.

sh IA M

Year oldest pipe installed ______ 2.

Type of pipe installation 4.

Box conduitSolid pour conduitTunnelPrefab conduit ,Direct Burial P0000,Other

dtos4w%6-4qe. o

Miles of pipe /Expansion devices

Slip joints 'Bellows


9 d#r., ,

5. Intervals between expansion devices 00+6041 feet V'-1406. Condensate return? yes no

7. Intervals between manholes 5z'o mo feet ras,

/r Aes4,-d

8 . Temperature and pressure Jia -3L6 F /)5-'$-o psi (HP steam)7--F - psi (LP steam)

F psi (hot water)

I_


Valves RollersWelds FlangesExpansion devices External corrosion -Other

L-P syp/c 1%

/ ! ~r( /

.a %.LL aV L~l" nG N .%iCuirrpnt TLeak Detpcti nB1

RprAw I

e 4 "TA

92



7)jy A Ov&j &'J 41/4w vii}, G4/Zss t 4 o - ;eb A$X me h4 Q i44,j , pp; v Qv/C

Joo -boao y ,4. What is the ac acy of your location methods' 4 .Ze. /J6 r 6


1. Would you be interested ir using an acoustic system asdescribed earlier? V yes no

2. If not, wh-r not?

avw~+ to o,.. 4 A,r f7 .



6i? Ongoing system for monitoring, detection and locationb. A system for use as necessary to locate leaks detected

through other means

5. Would yo be interested in field testing a prototype system?

yes no

cms\leaksurv

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0

11,004- ew 60 400001 44 41d 00 41WA Z-0 001-1

93

N

C

P

A

1

3


ame of System /'I4kj 4 5 zAg I

ontact Name Gz- 29/14%

hone /) - 39#- 6 7


. Year oldest pipe installed 2. Mi

. Type of pipe installation 4. Ex

Box conduit _____5

Solid pour conduit BeTunnel BaPref ab conduit __/_E_

D i r e c t B u r i a l O t h e rO tOther

Intervals between expansion devices ?o.'_9 O eet

Condensate return? / yes no

Intervals between manholes a-i/ feet S o A d .' ze,

Temperature and pressure g06 F >Sb psi (HP steam)3j5-F 15'Opsi (LP steam)--y ,-k%

F psi (hot water)

Current Leak Detection &4o 4


Valves t0WeldsExpansion devices Cv

Other

ko*~ *YW6%A s7)P dJ,*



,t

les of pipe

pansion devices

ip joints

allowsLll joint VCp. loopother

5.

6.

7.

8.

//Jv ;

94





1. Would you be interested in using an acoustic system asdescribed earlier? Vyes _ no

2. If not, why not? / 4




through other means

5. Wouldou be interested in field testing a prototype system?

yes no

cms\leaksurv

Name of System

Contact Name

Phone

95


Il, 44--,;; lterIVO L3 -- 8-a

$12- 3 i- 680o


. Year oldest pipe installed /9L7g 2. Miles of pipe


Box conduit Slip joints VSolid pour conduit BellowsTunnel Ball joint L7r/ "Prefab conduit Exp. loop ,CsDirect Burial _ _Other

Other

/n'1 I- 7' 001,V064 -,

" ,ow 4' ~ '~'~ -4~

5.

6.

7.

Intervals between expansion devices 0Ot feet 4 Gc'4


Intervals between manholes (oj- oofeet

8. Temperature and pressure 9/0 F ' S psi3 c F 'o psi

)?--o F r--s psi

(HP steam)(LP steam)(h.e-wat.e).


1. What types/locat.ons of leaks are your biggest problem?

Valves RollersWelds FlangesExpansion devices External corrosionother

A

1

:3

96


"/ '7,




1. Would you be interested ir using an acoustic system asdescribed earlier? c/ yes __ no

2. If not, why not? , 92 --/, ,



a. Ongoing system for monitoring, detection and location69 A system for use as necessary to locate leaks detectedthrough other means

5. Wouldyou be interested in field testing a prototype system?

yes no

cus\leaksurv

97

Name of

Contact

Phor

1.

3.

System

Name


w4"/ k/'s,./ ,g l "

3/7-- p6 /-- N893

distribution System

Year oldest pipe installed /



2.

4.

Miles of pipe

Expansion devices

Slip jointsBellows


/fZ/<.l/nit fA s //O

/Uoo 4&4 4 xti.




8. Temperature and pressure FFF

psipsi

____ psi





5.

6.

7.

le

D~

Aab~Aw /rc -A

mlm

98





1. Would you be interested in using an acoustic system asdescribed earlier? yes ~-' no

2. If not, why not?



a.b.



yes no

cms\leaksurv

99

Name of System

Contact Name

Phone


S5A'~1 ...-

6/~- 9a4-/5O


Y41-v ? ?2

64e zG

1. Year oldest pipe installed /7 7f 2. Miles of pipe


Box conduit Slip joints __Solid pour conduit BellowsTunnel t/ ('Jk- Ball jointPrefab conduit Exp. loopDirect Burial ___Other

Other

5. Intervals between expansion devices c2 0O0 f eet --- ?f> d


7. Intervals between manholes odi feet

8. Temperature and pressure _ _' F /3', psiF psi

F ____ psi



1. What types/locations of leaks are your biggest probUlm?

ValvesWeldsExpansion devicesOther 4 4

Rollers

FlangesExternal corrosion j.

M !

100





1. Would you be interested in using an aco tic system asdescribed earlier? __ yes ___no

2. If not, why not?




through other means


yes no

cms\leaksurv

101

Name of System

Contact Name

Phone


/ ;Ley-, /'6.$4-e f 4 .- 1J4.


. Year oldest pipe installed 2. Mile:

. Type of pipe installation 4. Expa

Box ccr~duit _ __Slip

Solid pour conduit BellTunnel Ball

Prefab conduit Exp.Direct Burial _____eOthe

Other

5.

6.

7.

s of pipe

nsion devices

joints

ows

joint

loop

r




8. Temperature and pressure ___ F _____ psi (HP steam)F psi (LP steam)

32 7S F >o sopsi (hot water)

B. Current Leak Detection "; 61 % A1. What types/locations of leaks are your biggest problem?

Valves RollersWelds FlangesExpansion devices '/ External corrosion T7Other

A

1

3

4?1)1310pl

I

102


- V/Sid 4e SiSr,

-4^-,A cV .i e7o


yv~k /-Zo4e




2. If not, why not?

3. What would increase t:-Ls system's usefulness to you?


a. Ongoing system for monitoring, detection and location.7A system for use as necessary to locate leaks detected

throu h other means

5. Would you be interested i47 field testing a prototype system?

yes __no

cms\leaksurv

103

LA DETECTION SURVUT

ame of System IV i? 6 - -- ' ' / -I eontact Name ,L 4VA -'V

hone _ _ _ _ _ _,__

.Distribution System

. Year oldest pipe installed /X..3 2. Miles of pipe 5

. Type 0 pipe installation 4. Expansion devices

Box condUittj) ' I 4 /, 4 /.,) Slip joints t/ ~ :solid pour conduit BellowsTunnel Ball jointPrefab conduit Exp. loopDirect Burial Other

Other

/V 6 ^4O7 04 4

5.

6.

7.

Intervals between expansion devices __JO feet -- /o ,r ,.


Intervals between manholes 600 feet

8. Temperature and pressure _____ F to psi (HP steam)F psi (LP steam)F _____ psi (hot water)

B. Current Leak Detection 23 S 1/""00 e&V1. What types/locations of leaks are your biggest problem?

Valves RollersWelds FlangesExpansion devices External corrosionOther -

Ilivame-4A A, 0A k 0DJ

N4

CI

A

1

3

i,4)

/.,Owor " z4g4,

$--f a. ,rte

-

104




C. Use of Acoustic System -kS-

1. Would you be interested ?.n using an acoustic system asdescribed earlier? _ yes _ no

2. If not, why not?



a. Ongoing system for monitoring, detection and locationA system for use as necessary to locate leaks detectedthrough other means ,.., ' .

4*- fh- '4( Seti5. Would y9be interested in field testing a prototype system?

yes no

cms\leaksurv

105

Nam

Coni

Phoi

A.


e o System

tact Name ___________: ______

ne istr~ibut2i-~nS

Distribution System



Box conduit

Solid pour conduitTunnelPxrefat cbnduitDirect Burial

Other

2.

4.

Miles of pipe

Expansion devices

Slip jointsBellows

Ball jointExp. le'pOther



7. Intervals between manholes feE

36s5~8. Temperature and pressure 3fJ'F

FF

feet

no

et

5'~S psipsipsi




Valves Rollers


(.f 1*a~-4 Av4 Ld

,14n

1.

3.

.m mmMOMMOMMA e

45e,1 l.prry t

ati P, l ova

106





1. Would you be interested in using an ac ustic system asdescribed earlier? yes _ no

2. If not, why not?

3. What would irease this system's usefulness to you?



through other means


yes no

cms\leaksurv

107

LEA DETECTION SURVEY

ame of System P Ae d -

ontact Name /t A 714*,,

hone /__ -73_38,_ _

.Distribution System

. Year oldest pipe installed /9/1/ 2.

. Type of pipe installation 4.

Box conduitSTPDC

N

C

P

A

1

3

olid pour conduit i Bellowstunnell Ball joint

prefab conduit Exp. loop

irect Burial Other

there

q 7 Ai;471

Intervals between expansion devices feet V44

Condensate return? yes _

Intervals between manholes feet -/,.

8. Temperature and pressure 35 FFF

/ar psipsipsi





Expansion devices External corrosionother

50"w WW w' ~w

rep 4'4

Miles of pipe /' r

Expansion devices

Slip joints

5.

6.

7.

t

r

I "/A

A0.0 C"Voc

A lrvr,*ma C,00,.

108


3. How are leaks located? 1 ? 1d >'E'Anre ty fc



1. Would you be interested in using an a stic system asdescribed earlier? _ yes no

2. If not, why not?




through other means


yes no

cms\leaksurv

109

Name of System

Contact Name

Phone


'j/Q - 6 c - 7Y


. Year oldest pipe installed


Box conduitSolid pour conduitTunnel 7'4-5'&-= 40, .Prefab conduitDirect BurialOther

2.

4.

Miles of pipe i 7

Expansion devices

Slip joints _____

Bellows _ _


4 Vk4Ole$

Intervals between expansion vices feet V'

Condensate return? _ yes no

Intervals between manholes feet vwzA,

8. Temperature and pressure _____ F _0_ ps:F-ps

SP01~, /J-6 e0'-1 ____ F ____ps.


1. What types/locations of leaks are your big

Valves RollersWelds FlangesExpansion devices __e' Externalother 00^4-

ii


gest problem?

corrosion

A

1

3

5.

6.

7.

v " . i

110

2. How are leaks detected now? C & z;b,ro --rSa" 6$ist, j


www- 1-,; / vfL v*1re~f



1. Would you be interested ijusing an acoustic system asdescribed earlier? yes no

2. If not, why not? 4e en r7.

0t~ 47- ~,cow bA~e



a. Ongoing system for monitoring, detection and location(. A system for use as necessary to locate leaks detectedthrough other means


I yes no I 1v 6/. .

6&~, cyer6e

cms\leaksurv

111

Nc

Cc

P]

1

3

Intervals between expansion devices /a -/5d feet

Condensate return? _ _yes no

Intervals 'between manholes /e-'6o feet

5.

6.

7.

8. Temperature and pressure y/ob F ? 20 psi (HP steam)F _ psi (LP steam)F psi (hot water)

B. Current Leak _Detection ''0 /'M 0


Valves RollersWelds FlangesExpansion devices External corrosionOther M

LFI7X DETECTION SURVEY

ame of System

intact Name d,/ //---

hone y2 - - . / D 'Of


. Year oldest pipe installed 2. Miles of pipe /


Box conduit Slip jointsSolid pour conduit 7 Bellowsit______Tunnel Ball joint

Prefab conduit Exp. loopDirect Burial Other

Other

d*u eI~ 1

Or/t /

V

112


3. How are leaks located? p24 d Jf4 p




2. If not, why not?




5. Would y be interested in field testing a prototype system?

yes no

cms\leaksurv

113


Name of System

Contact Name _ _ _ _ ....g. _ _ _ _


1. Year oldest pipe installed /9ftcs


2. Miles of pipe




/ ftl -751OS7'

A1& 4 vwd &



7 . Intervals between manholes ' j a;sfeet 57 o

8. Temperature and pressure 3rD0 F 1 r' psiQie -37J F >, -.0 psi

F psi

feet /4'.re

'- no

Cp




ValvesWeldsExpansionOther

RollersFlangesExternal corrosiondevices

/VorA- t-,*

'A44 44 ; - Ox-

Phone

v4 ~V.J-Js

~~

A-O O ex /;Z ad

114


Aa~a/ ,4fi A rAv//




1. Would you be interested in using an acoustic system asdescribed earlier? yes .-~no

2. If not, why not?' ' I o(9p


1t14q 'i'y h *e ,, A ate~'- .

4. Are you interested in: 4 4


through other means


yes _no

cms\leaksurv

115

N

C

P

A

1

3

LMA DETECTION SURVEY

ame of System /AMc 2c,, Z'c4-g i

ontact Name 4 4

hone ~/i- Y6-'" d'$-

. Distribution System / E'a' , /A ' '

. Year oldest pipe installed /9d r 2. Miles of pipe JType of pipe installation 4. Expansion devices

Box conduit CM /id V~Slip joints VSolid pour conduit BellowsTunnel Ball jointPrefab conduit Exp. loop TDirect Burial Other

Other

InAr0 744 n 4 sle

14,



7. Intervals between manholes fe

8. Temperature and pressure SS3 FF _

F _

feet

/- no

at

,; O psi (HI__psi (LI__psi (h4

V t(y

P steam)P steam)ot water)


1. What types/locations -of leaks are




1

116



N 7 k 4 / sGam


C. Use of Acoustic_ System

1. Would you be interested in using an aoustic system asdescribed earlier? yes V no

2. If not, why not?747 - 4




through other means


yes no

cms\leaksurv

N

CI

PI

A

1

3

117

LEAK DETECTION PURVEY

ame of System1

ontact Name)/ s'p,29.v v ~

hone __ -________- _____


. Year oldest pipe installed /A'P0, 2. Miles of pipe /PS'


Box conduit Slip jointsSolid pour conduit / BellowsTunnel Ball joint

Prefab conduit Exp. loopDirect Burial -_OtherOther

Or 0'0

5. Intervals between expansion devices feet


7. Intervals between manholes sO'Ofeet d64

8. Temperature and pressure_ FFF

/ 20 psi

psi




Valves RollersWelds FlangesExpansion devices External corrosion A- POther

i .

rr.ry

0

u

/?444 e7olo;




A'4' i1 "


1. Would you be interested in using an a ustic system asdescribed earlier? _ yes _ no

2. If not, why not?




through other means


yes no

cms\ leaksurv

119

LFi DETECTION SURVEY

Name of System

Contact Name

Phone S/y


I >/- 750o



2. Miles of pipe


l/Ji Box conduitSolid pour conduitTunnel

/W/" Prefab conduitDirect BurialOther

/0000,a/ Slip joints

, '/g "P 4~BellowsCr 9 Ball joint

/ Exp. loopOther

#7 J/y 6~ra.iva--ow -se , a&Gl



020D feet

no

7. Intervals between manholes 4 0Ao feet



FFF

psipsipsi




RollersFlangesExternal corrosion -

(Mre oc PQ,,, 4d v a l, '-3 a l..

tY 6- )

J-,, 72M-,

0

N fyi z e DuerOPP

..

120


3. How are leaks located? / 5 , te z,4A. ,s 4



1. Would you be interested iusing an acoustic system asdescribed earlier? yes _ no

2. If not, why not? sg~ f




c


yes no

cs\leaksurv

121


T_ _i "A -L J_ ' I,Name of System / 0/V

Contact Name & 'r~ _

Phone V/4 ~ - rJ ?


1. Year oldest pipe installed iAi4 /9/6,r 2.

3. Type of pipe installation 4.

Box conduit

Solid pour conduitTunnel _______ g

Prefab conduitDirect Burial _/ _

Other

Miles of pipe /c2

Expansion devices

Slip joints ___.__

BellowsBall jointExp. loopOther

ca 4 /4 r,), ,

Intervals between expansion devic

Condensate return? Yes

Intervals between manholes


es feet v w

no f eet v%

feet *,

_5 psiS- psi

psi


Current Leak Detection

What types/locations of leaks are your biggest problem?

Valves Rollers ___

Welds FlangesExpansion devices i7 External corrosionOther

/VAv 7 A ~ A ~

5.

6.

7.

1.

IMP 1%% 40, dho loop LL= dsmy Ifto ftab a 4bw %No wag Amm, Z WI.B.

122


- GkG




1. Would you be interested in using an acoustic system asdescribed earlier? _ yes no

2. If not, why not?




through other means


yes no

c7 \leaksurv

Name of System

Contact Name

Phone

123

LEAE DETECTION SURVEY

a ZAdpy'7L Z .


1. Year oldest pipe installed ____3_


Box conduit

Solid pour conduitTunnel

Prefab conduitDirect Burial

Other

6 7":4-a7 .

~-q' 4zJ.

2.

4.

Miles of pipe

Expansion devices

Slip jointsBellows

Ball jointExp. loop ___

Other



Intervals between manholes a37' * feet

8. Temperature and pressure_ FF

M, -- v F

psipsi

J psi


What types/locations of leaks are

ValvesWeldsExpansion devicesother


RollersFlanges -External corrosion

5.

6.

7.

1.

. %A4 6I~-" %p a G +1I .B Current Leak Detection

h4 de

124





1. Would you be interested in using an acoustic system asdescribed earlier? V yes no

2. If not, why not?




through other means

5. WouldAou be interested in field testing a prototype system?

yes _no

cms\leaksurv

Name of System

Contact Name

Phone

125

LF DETECTION SURVEY

5/- 9'S/ 4- / V-- 9/ r4 .n


. Year oldest pipe installed


Box conduit


Prefab conduitDirect Burial

Other

c~~ i 4dr j a J y d ' // wj ,J

2.

4.

Miles of pipe jf

Expansion devices

Slip pointsBellows

Ball jointExp. loop

Other

01 A t 14,"~"





psipsipsi




Valves RollersWelds FlangesExpansion devices ___External corrosionOther

0,e ,

A

1

3

5.

6.

7.

4

r i . i i

C?)/ 31.1 /

.

126






2. If not, why not?

3. What would increase this system's usefulness .o you?



through other means


yes no

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127

N;

C4

P1

1

3

5.

6.

7.

!- 427p. 1'o1


ame of System' 2r' c

ontact Name IOU,2o,)rorhone _S__ '__--__ _.


. Year oldest pipe installed ' /905' 2. IN

. Type of pipe installation 4. E

Box conduit _


Prefab conduitDirect Burial COther

Intervals between expansion devices ____ feet


Intervals between manholes So -/ owfeet

8. Temperature and pressure 3ro Fs-b F

F

/g- psir- psi

psi






Rollers

FlangesExternal corrosion ,-

!/X'4,4 P'

60021, I, 1tA4

4iles of pipe 7

Expansion devices

lip jointsBellowsBall jointExp. loopether

40fo //;tao 6 Y!R4 oeb q 4 4m 40

40v%;4 ljkX

128





1. Would you be interested in using an acoustic system asdescribed earlier? "jyes no




through other means

5. Wou lou be interested in field testing a prototype system?

yes no 4

cms\leaksurv

129

Name of System

Contact Name

Phone

A. Distributi


#9 39 /-r', 7 /'aA A 25 OE 2 -]9%-- 7& 5~/



Box conduit

Solid pour conduitTunnelPrefab conduitDirect Burial

Other

2.

4.

Intervals between expansion devices





FF

3SaF

Miles of pipe 899

Expansion devices

Slip joints

Bellows

Ball jointExp. loopOther -

feet

no


psipsipsi



S'icE",14 k yds

A'.~4 / 1eg

/I' op-- a 4 t? x o

1.

3.

5.

6.

7.

on System

.

130


22~74 Jrtez,. ,/ e e.e



/i -V


1. Would you be interested in using an oustic system asdescribed earlier? yes no

2. If not, why not?




through other means


yes no

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Ors !moo 4eAv6wp o4e 6vz-, -J JAS4P-

N

C

P

A

1

3

Intervals between expansion devices -ioj feet


intervals between manholes /O' feet - -2ase .7 - /De




ValvesWeldsExpansion devices ~./ /' 3other

j psi (HP steam)psi (LP steam)psi (hot water)


Rollers


131


ame of System 7r'- X 4 , 6 k

ontact Name 4 hone -- D ir-- *

hone ______________ &f.


. Year oldest pipe installed l1O 2. Miles of pipe cP


Box conduit Slip joints i~Solid pour conduit Bellows /

Tunnel Ball jointPrefab conduit Exp. loop

Direct Burial Other

Other

5.

6.

7.

A 40

Dr.4, Cc vim, Gx.G,

132



4. whatst4 ur



1. Would you be interested i sing an acoustic system asdescribed earlier? yes no

2. If not, why not?




through other means


yes no o Ss,, *

cms\leaksurv

T4

133

Distribution for ANL-92/5

Internal:

W. E. Brewer W. P. Lawrence R. W. WeeksH. Drucker C. A. Malefyt (2) ANL Patent Dept.N. Heeg A. C. Raptis ANL Contract FileD. E. Karvelas S. H. Sheen TIS Files (3)D. S. Kupperman (50) C. E. TillR Lanham R. A. Valentin

External:

DOE-OSTI, for distribution per UC-350 (331)ANL Libraries (3)DOE Chicago Operations Office:

ManagerF. Herbaty

Materials and Components Technology Division Review Committee:H. Berger, Industrial Quality, Inc., Gaithersburg, MDM. S. Dresselhaus, Massachusetts Institute of Technology, Cambridge, MAS. J. Green, Electric Power Research Institute, Palo Alto, CAR. A. Greenkorn, Purdue University, West Lafayette, INC.-Y. Li, Cornell University, Ithaca, NYP. G. Shewmon, Ohio State University, ColumbusR. E. Smith, Electric Power Research Institute, NDE Ctr., Charlotte, NC

Elaine K. Allen, Green & Associates, DallasMr. Mark Anderson, NRG Thermal, MinneapolisCarl E. Avers, Catalyst Thermal Energy Corp., Youngstown, OHMark Avers, Baltimore Steam Co., BaltimoreArturo F. Barcena, Medina, NYJeffrey P. Bees, Youngstown Thermal Corp., Youngstown, OHLeif Bergquist, Trigen Energy Corp., New YorkIver Blackberg, Blackberg Assoc., Arlington Heights, ILTimothy Block, Detroit Edison Co., DetroitDavid Bonkovich, Heath Consultants, Inc., Belle Vernon, PAJames R. Brooks, Baltimore Steam Co., BaltimoreRudy Brynolfson, St. Paul, Inc, St. PaulFrederick Callowhill, Exec. Dir., IDHCA, Sanford, NCJohn M. Casey, Univ. of Georgia, AthensWyndham Clarke, U.S. Dept. of Housing & Urban Dev., Washington.Lewis C. Cohen, Philadelphia Thermal Corp., PhiladelphiaFloyd Collins, DOE, WashingtonRobert O. Couch, RPSI, Inc., Brecksville, OHMr. M. Danbo, J.C. Hempel's Handelssus A/S, Copenhagen K, DenmarkGlen H. Fukuda, Fukuda Intl., Lafayette, CA

134

Jack Gleason, WashingtonBill Goodwin, Harrisburg SW, Ltd., Harrisburg, PAGary Gustafson, MEC, MinneapolisJames F. Harley, Intergy, Inc., Brecksville, OHGene Hess, Wisconsin Elec. Power Co., MilwaukeeDavid F. Hobson, IDHCA, WashingtonJay Holmes, USDOE, WashingtonLeslie J. Jardine, Bechtel National, Inc., San FranciscoLoraine Kasprzak, Consolidated Edison Co. of New York, Inc., New YorkJack Kattner, MEC, 1060 IDS Center, Minneapolis, MNP.G. Kemp, GAP Technologies, Menlo Park, 0102, South AfricaBrian Kirk, Consolidated Edison, New YorkY. Kitaura, Sumitomo Chemical America, Inc., New YorkJohn Kuhns, Catalyst Energy Dev. Corp., New YorkWilliam Mariutto, KAFA Intl., Rivera Beach, FLRichard Mayer, PG&E Co. San FranciscoMichael E. McKay, Princeton Univ., PrincetonDr. William Messner, Consolidated Edison R&D, New YorkAnthony C. Mirabella, Energy Networks Inc., Hartford, CTMichael J. Nagel, Univ. of Minnesota Plant, MinneapolisE. W. Ng, Consolidated Edison, New YorkHans Nyman, St. Paul, Inc., St. PaulYousuf H. Al Omar, United Gulf Construction Co. WLL, Safat, KuwaitIshai Oliker, Burns and Roe, Ordell, NJSeth J. Perkinson, III, The Perkinson Co., Charlotte, NCRobert J. Perry, Heath Consultants, Inc., Stoughton, MAEugene Peters, 301 N. Amin Ave., Scranton, PASigrid H. Pilgrim, Intercon Research Associates, Ltd., Evanston, ILChristopher Pioli, Dept. of Utilities-Gas Division, Colorado Springs, CODean Price, Georgetown University, WashingtonW.L. Puckering, W.L. Puckering Consulting, Inc., Vancouver, B.C.Hermine Randall, Univ. of Mass./Amherst, Amherst, MAZeph Regnier, 140 Promenade du Portage Phase IV Lv2, Hull, Quebec KiA OM3Anders Rydaker, District Energy Systems, Roseville, MNPaul J. Sausville, Bulk Storage Section, Div. of Water, AlbanyRoger E. Scholl, URS/John A. Blume & Associates, San FranciscoBeth Schumake, Neotronics North America, Inc., Gainesville, GAMark Spurr, Resource Efficiency, Inc., St. PaulDarrell D. Stalzer, Iowa EL & P Co., Cedar Rapids, IAFred Strnisa, NY State Energy R&D Auth., AlbanyDavid W. Wade, Resource Dev. Assoc., Inc., Atlanta, GAGalen Young, Fisher Research Lab., Los Banos, CA

and Review of Current Technology and Practices/67531/metadc... · 1 Introduction The cost of building and maintaining thermal distribution systems contributes substantially to the

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